import numpy as np from recommendations.county_to_region import county_to_region_map # This data comes from SPONs 2023 regional_labour_variations = [ {"Region": "Outer London", "Adjustment_Factor": 1.00}, {"Region": "Inner London", "Adjustment_Factor": 1.05}, {"Region": "South East England", "Adjustment_Factor": 0.96}, {"Region": "South West England", "Adjustment_Factor": 0.90}, {"Region": "East of England", "Adjustment_Factor": 0.93}, {"Region": "East Midlands", "Adjustment_Factor": 0.88}, {"Region": "West Midlands", "Adjustment_Factor": 0.87}, {"Region": "North East England", "Adjustment_Factor": 0.83}, {"Region": "North West England", "Adjustment_Factor": 0.88}, {"Region": "Yorkshire and the Humber", "Adjustment_Factor": 0.86}, {"Region": "Wales", "Adjustment_Factor": 0.88}, {"Region": "Scotland", "Adjustment_Factor": 0.88}, {"Region": "Northern Ireland", "Adjustment_Factor": 0.76} ] # This data is based on the MCS database MCS_SOLAR_PV_COST_DATA = { "last_updated": "2024-01-04", "average_cost_per_kwh": 2013.94, "average_cost_per_kwh-Outer London": 2618.75, "average_cost_per_kwh-Inner London": 2618.75, "average_cost_per_kwh-South East England": 2083.33, "average_cost_per_kwh-South West England": 2113, "average_cost_per_kwh-East of England": 1973.86, "average_cost_per_kwh-East Midlands": 1981.86, "average_cost_per_kwh-West Midlands": 1926.55, "average_cost_per_kwh-North East England": 2028.49, "average_cost_per_kwh-North West England": 1620.42, "average_cost_per_kwh-Yorkshire and the Humber": 2060.9, "average_cost_per_kwh-Wales": 1898.83, "average_cost_per_kwh-Scotland": 1967.97, "average_cost_per_kwh-Northern Ireland": 2126.09, } # This is based on quotes from installers BATTERY_COST = 3500 # This is based on https://www.checkatrade.com/blog/cost-guides/cost-smart-thermostat/ SMART_APPLIANCE_THERMOSTAT_COST = 400 PROGRAMMER_COST = 120 ROOM_THERMOSTAT_COST = 150 TRVS_COST = 35 # Cost for TTZC # Smart thermostat based on checkatrade https://www.checkatrade.com/blog/cost-guides/cost-smart-thermostat/ # Based on the Nest system TTZC_SMART_THERMOSTAT_COST = 205 TTZC_SMART_THERMOSTAT_LABOUR_HOURS = 2 TTZC_ELECTRICIAN_HOURLY_RATE = 45 # Based on cost of a Nest temperature sensor TTZC_ROOM_TEMPERATURE_SENSOR_COST = 50 TTZC_ROOM_TEMPERATURE_SENSOR_LABOUR_HOURS = 0.17 # (Assume ~ 10 mins install per sensor) # Basedon an average cost of smart radiator values TTZC_SMART_RADIATOR_VALUES = 50 TTZC_SMART_RADIATOR_VALUES_LABOUR_HOURS = 0.37 # (Assume ~ 15-30 mins install per valve) # Low carbon combi boiler - median value based on £2200 - £3000 range LOW_CARBON_COMBI_BOILER = 2200 # boiler prices based on # https://www.greenmatch.co.uk/boilers/30kw-boiler # https://www.greenmatch.co.uk/boilers/35kw-boiler # https://www.greenmatch.co.uk/boilers/40kw-boiler # These are exclusive of installation costs COMBI_BOILER_COSTS = { "30kw": 1550, "35kw": 1610, "40kw": 1625 } CONVENTIONAL_BOILER_COSTS = { "30kw": 1117, "35kw": 1546, "40kw": 1776 } class Costs: """ A class to calculate the costs associated with construction works, specifically focusing on cavity wall insulation. It includes contingency, preliminaries, profit margin, and VAT calculations. As a sense check, there is a useful article from checkatrade on retrofitting and expected costs: https://www.checkatrade.com/blog/cost-guides/retrofit-insulation-cost/ Another useful article for benchmarking the cost of floor insulation: https://www.checkatrade.com/blog/cost-guides/floor-insulation-cost/ """ # Contingency is a percentage of the total cost of the work and covers unforseen expenses # We assume a conservative 10% contingency for all works which is a rate defined by SPONs CONTINGENCY = 0.1 # For flat roof, we assume it's a high risk project as it's very weather dependent and also is heavily # dependent on the quality of the existing roof FLAT_ROOF_CONTINGENCY = 0.15 # We use a higher contingency rate for internal wall insulation because of the potential for issues with moving # fittings and trimming doors, as well as scope for damage to the existing wall during preparation. IWI_CONTINGENCY = 0.2 # Where there is more uncertainty, a higher contingency rate is used HIGH_RISK_CONTINGENCY = 0.2 # When there is less uncertainty, a lower contingency rate is used LOW_RISK_CONTINGENCY = 0.05 # Preliminaries are a percentage of the total cost of the work and covers the cost of site-specific costs # such as site preparation, safety measures and project management. This rate can vary but we'll assume a 10% # rate, on the total cost before VAT, as recommended by SPONs PRELIMINARIES = 0.1 # For higher risk projects, a higher preliminaries rate is used. SPONs indicates that a higher risk project might # have a preliminaries of 12-14% so we use 12% as the median for the preliminaries rate. # For External wall insulation (EWI), we use 15% as the preliminaries rate if we think the property might # need scaffolding, otherwise we use 12%. This is to account for any site preparation that might be required EWI_NO_SCAFFOLDING_PRELIMINARIES = 0.2 EWI_SCAFFOLDING_PRELIMINARIES = 0.25 VAT_RATE = 0.2 PROFIT_MARGIN = 0.2 # Based on this greenmatch article, on average, a Sash window is around 50% more expensive than a casement window. # Therefore, for a conservative cost estimate, and allowance for a more premium window type, we inflate the material # cost of the windows to allow for a sash window type # https://www.greenmatch.co.uk/windows/double-glazing/cost SASH_WINDOW_INFLATION_FACTOR = 1.5 # Typically, secondary glazing can be installed for 25% of the cost of double glazed windows - to be conservative, # we scale the cost by half SECONDARY_GLAZING_SCALING_FACTOR = 0.5 def __init__(self, property_instance): """ Initializes the Costs class with a property instance. :param property_instance: Instance of a Property class containing relevant details like wall area. """ if not hasattr(property_instance, 'insulation_wall_area'): raise ValueError("Property instance must have an 'insulation_wall_area' attribute") self.property = property_instance self.regional_labour_variations = regional_labour_variations self.region = county_to_region_map.get(self.property.data["county"], None) if self.region is None: # Try and grab using the local-authority-label self.region = county_to_region_map.get(self.property.data["local-authority-label"], None) if self.region is None: raise ValueError("Region not found in county map") self.labour_adjustment_factor = [ x["Adjustment_Factor"] for x in self.regional_labour_variations if x["Region"] == self.region ][0] if not self.labour_adjustment_factor: raise ValueError("Labour adjustment factor not found") def cavity_wall_insulation(self, wall_area, material): """ Calculates the total cost for cavity wall insulation based on material and labor costs, including contingency, preliminaries, profit, and VAT. Because of some limitations in the SPONs data, there are no materials that can be blown through a wall, therefore we have adapted similar materials, basing our estimates on 75mm cavity slabs, and have halved the labour time required. That is why we still price based on wall area despite volume actually being the correct metric. :return: A dictionary containing detailed cost breakdown. """ material_cost_per_m2 = material["material_cost"] base_material_cost = material_cost_per_m2 * wall_area labour_cost = material["labour_cost"] * wall_area * self.labour_adjustment_factor subtotal_before_profit = base_material_cost + labour_cost contingency_cost = subtotal_before_profit * self.CONTINGENCY preliminaries_cost = subtotal_before_profit * self.PRELIMINARIES profit_cost = subtotal_before_profit * self.PROFIT_MARGIN subtotal_before_vat = subtotal_before_profit + contingency_cost + preliminaries_cost + profit_cost vat_cost = subtotal_before_vat * self.VAT_RATE total_cost = subtotal_before_vat + vat_cost labour_hours = material["labour_hours_per_unit"] * wall_area # Assume a team of 2 labour_days = (labour_hours / 8) / 2 return { "total": total_cost, "subtotal": subtotal_before_vat, "vat": vat_cost, "contingency": contingency_cost, "preliminaries": preliminaries_cost, "material": base_material_cost, "profit": profit_cost, "labour_hours": labour_hours, "labour_cost": labour_cost, "labour_days": labour_days } def loft_insulation(self, floor_area, material): """ Calculates the total cost for cavity wall insulation based on material and labor costs, including contingency, preliminaries, profit, and VAT. :return: A dictionary containing detailed cost breakdown. """ material_cost_per_m2 = material["material_cost"] # We inflate material costs due to recent price increases material_cost_per_m2 = material_cost_per_m2 * 1.5 base_material_cost = material_cost_per_m2 * floor_area labour_cost = material["labour_cost"] * floor_area * self.labour_adjustment_factor subtotal_before_profit = base_material_cost + labour_cost # We use high risk contingency because of the possibility of access issues and clearing existing insulation contingency_cost = subtotal_before_profit * self.HIGH_RISK_CONTINGENCY preliminaries_cost = subtotal_before_profit * self.PRELIMINARIES profit_cost = subtotal_before_profit * self.PROFIT_MARGIN subtotal_before_vat = subtotal_before_profit + contingency_cost + preliminaries_cost + profit_cost vat_cost = subtotal_before_vat * self.VAT_RATE total_cost = subtotal_before_vat + vat_cost labour_hours = material["labour_hours_per_unit"] * floor_area # Assume a team of 1 person labour_days = labour_hours / 8 return { "total": total_cost, "subtotal": subtotal_before_vat, "vat": vat_cost, "contingency": contingency_cost, "preliminaries": preliminaries_cost, "material": base_material_cost, "profit": profit_cost, "labour_hours": labour_hours, "labour_cost": labour_cost, "labour_days": labour_days } def internal_wall_insulation(self, wall_area, material, non_insulation_materials): """ Broadly speaking, the high level steps to an internal wall insulation job are the following: 1) Demolition: This involves removing existing wall linings, fittings, and any other obstacles. It's important to factor in the disposal of debris and the potential need for additional protective measures to ensure the safety of the work area. 2) Insulation Installation: This is the core part of the process where the chosen insulation material is applied. The choice of insulation material will depend on several factors including thermal performance, wall construction, and space constraints. 3) Vapour Barrier Installation: This is crucial for preventing moisture from penetrating the insulation, which can compromise its effectiveness and lead to mold growth. 4) Re-decoration: This involves applying plaster to the wall and then painting. The quality of finish here is important for both aesthetic and functional reasons. 5) Trim and Finishing Work: Post-insulation, tasks such as re-installing skirting boards, door frames, or window sills might be necessary. :return: """ # Extract and check the different types of data we'll need demolition_data = [x for x in non_insulation_materials if x["type"] == "iwi_wall_demolition"] vapour_barrier_data = [x for x in non_insulation_materials if x["type"] == "iwi_vapour_barrier"] redecoration_data = [x for x in non_insulation_materials if x["type"] == "iwi_redecoration"] if not demolition_data: raise ValueError("No data found for iwi_wall_demolition") if (len(vapour_barrier_data) != 1) or (len(redecoration_data) != 3): raise ValueError("Incorrect number of data entries for non-insulation materials") # Break out the individual material costs # Since we don't know the exact wall construction, we take an average for demolition costs, since # the cost will depend on the type of wall construction demolition_material_costs = np.mean([x["material_cost"] * wall_area for x in demolition_data]) insulation_material_costs = material["material_cost"] * wall_area vapour_barrier_material_costs = vapour_barrier_data[0]["material_cost"] * wall_area redecoration_material_costs = sum([x["material_cost"] * wall_area for x in redecoration_data]) demolition_plant_costs = np.mean([x["plant_cost"] * wall_area for x in demolition_data]) # Again for demolition, we average since we aren't sure which demolition process will be used demolition_labour_costs = np.mean([x["labour_cost"] * wall_area for x in demolition_data]) insulation_labour_costs = material["labour_cost"] * wall_area vapour_barrier_labour_costs = vapour_barrier_data[0]["labour_cost"] * wall_area redecoration_labour_costs = sum([x["labour_cost"] * wall_area for x in redecoration_data]) labour_costs = (demolition_labour_costs + insulation_labour_costs + vapour_barrier_labour_costs + redecoration_labour_costs) labour_costs = labour_costs * self.labour_adjustment_factor materials_costs = (demolition_material_costs + insulation_material_costs + vapour_barrier_material_costs + redecoration_material_costs) subtotal_before_profit = labour_costs + materials_costs + demolition_plant_costs contingency_cost = subtotal_before_profit * self.IWI_CONTINGENCY preliminaries_cost = subtotal_before_profit * self.PRELIMINARIES profit_cost = subtotal_before_profit * self.PROFIT_MARGIN subtotal_before_vat = subtotal_before_profit + contingency_cost + preliminaries_cost + profit_cost vat_cost = subtotal_before_vat * self.VAT_RATE total_cost = subtotal_before_vat + vat_cost demolition_labour_hours = np.mean([x["labour_hours_per_unit"] * wall_area for x in demolition_data]) insulation_labour_hours = material["labour_hours_per_unit"] * wall_area vapour_barrier_labour_hours = vapour_barrier_data[0]["labour_hours_per_unit"] * wall_area redecoration_labour_hours = sum([x["labour_hours_per_unit"] * wall_area for x in redecoration_data]) labour_hours = (demolition_labour_hours + insulation_labour_hours + vapour_barrier_labour_hours + redecoration_labour_hours) # To install internal wall insulation, a small to medium size project might be conducted by a team of 3-5 people labour_days = (labour_hours / 8) / 4 return { "total": total_cost, "subtotal": subtotal_before_vat, "vat": vat_cost, "contingency": contingency_cost, "preliminaries": preliminaries_cost, "material": materials_costs, "profit": profit_cost, "labour_hours": labour_hours, "labour_days": labour_days, "labour_cost": labour_costs } def suspended_floor_insulation(self, insulation_floor_area, material, non_insulation_materials): """ We characterise the steps for suspended floor insulation as the following tasks: 1) Removal of Carpet and Underfelt: Where necessary, remove existing floor coverings to access the floorboards. 2) Removal of Floor Boarding: Carefully remove floorboards to access the space beneath for insulation. 3) Installation of Vapour Barrier: Install a vapour barrier to prevent moisture from affecting the insulation and floor structure. 4) Installation of Insulation: Fit the chosen insulation material between the joists in the floor void. 5) Refixing Floorboards: Replace and secure the floorboards after insulation installation. 6) Re-carpeting: Lay down the carpet or other floor coverings once the insulation and floorboards are in place. :return: """ demolition_data = [x for x in non_insulation_materials if x["type"] == "suspended_floor_demolition"] vapour_barrier_data = [x for x in non_insulation_materials if x["type"] == "suspended_floor_vapour_barrier"] redecoration_data = [x for x in non_insulation_materials if x["type"] == "suspended_floor_redecoration"] if (len(demolition_data) != 2) or (len(vapour_barrier_data) != 1) or (len(redecoration_data) != 2): raise ValueError("Incorrect number of data entries for non-insulation materials") # Break out the individual material costs demolition_material_costs = sum([x["material_cost"] * insulation_floor_area for x in demolition_data]) insulation_material_costs = material["material_cost"] * insulation_floor_area vapour_barrier_material_costs = vapour_barrier_data[0]["material_cost"] * insulation_floor_area redecoration_material_costs = sum([x["material_cost"] * insulation_floor_area for x in redecoration_data]) demolition_labour_costs = sum([x["labour_cost"] * insulation_floor_area for x in demolition_data]) insulation_labour_costs = material["labour_cost"] * insulation_floor_area vapour_barrier_labour_costs = vapour_barrier_data[0]["labour_cost"] * insulation_floor_area redecoration_labour_costs = sum([x["labour_cost"] * insulation_floor_area for x in redecoration_data]) labour_costs = (demolition_labour_costs + insulation_labour_costs + vapour_barrier_labour_costs + redecoration_labour_costs) labour_costs = labour_costs * self.labour_adjustment_factor materials_costs = (demolition_material_costs + insulation_material_costs + vapour_barrier_material_costs + redecoration_material_costs) subtotal_before_profit = labour_costs + materials_costs # Because of the possiblity of damage to the existing floor, or difficulties associated to moving fittings, # we use a higher contingency rate contingency_cost = subtotal_before_profit * self.HIGH_RISK_CONTINGENCY preliminaries_cost = subtotal_before_profit * self.PRELIMINARIES profit_cost = subtotal_before_profit * self.PROFIT_MARGIN subtotal_before_vat = subtotal_before_profit + contingency_cost + preliminaries_cost + profit_cost vat_cost = subtotal_before_vat * self.VAT_RATE total_cost = subtotal_before_vat + vat_cost demolition_labour_hours = sum([x["labour_hours_per_unit"] * insulation_floor_area for x in demolition_data]) insulation_labour_hours = material["labour_hours_per_unit"] * insulation_floor_area vapour_barrier_labour_hours = vapour_barrier_data[0]["labour_hours_per_unit"] * insulation_floor_area redecoration_labour_hours = sum([x["labour_hours_per_unit"] * insulation_floor_area for x in redecoration_data]) labour_hours = (demolition_labour_hours + insulation_labour_hours + vapour_barrier_labour_hours + redecoration_labour_hours) # Assume a team of 3 people for a small to medium size project labour_days = (labour_hours / 8) / 3 return { "total": total_cost, "subtotal": subtotal_before_vat, "vat": vat_cost, "contingency": contingency_cost, "preliminaries": preliminaries_cost, "material": materials_costs, "profit": profit_cost, "labour_hours": labour_hours, "labour_days": labour_days, "labour_cost": labour_costs } def solid_floor_insulation(self, insulation_floor_area, material, non_insulation_materials): """ We characterise the steps for solid floor insulation as the following tasks: 1) Removal of Carpet and Underfelt: This is the initial stage where any existing floor coverings, like carpets, tiles, or linoleum, are carefully removed. This exposes the solid floor beneath, which is typically concrete. 2) Preparation of Flooring: This step is critical. It involves: - Cleaning the existing floor surface thoroughly to remove debris and ensure a flat surface. - Assessing and repairing any damage to the concrete floor. This might include filling cracks or leveling uneven areas. 3) Installation of a Damp Proof Membrane (DPM): Before installing insulation, a DPM is often laid down to prevent moisture from rising into the insulation and the interior space. This step is crucial in areas prone to dampness. 4) Install Insulation: The insulation, often in the form of rigid foam boards, is laid over the DPM. The choice of insulation material will depend on the desired thermal properties and the available floor height. Care is taken to minimize thermal bridges and ensure a snug fit between insulation boards. 5) Laying a New Subfloor: Over the insulation, a new subfloor is often installed. This could be a layer of screed (a type of concrete) or wooden boarding, depending on the specific requirements and preferences. 6) Re-decoration and Finishing Touches: Once the subfloor is in place and has set or dried (if necessary), the final floor finish can be applied. This might involve: - Laying new tiles, wooden flooring, or other chosen materials. - If you're planning to re-carpet, this would be the stage to do it. - Skirting boards may need to be refitted or replaced. 7) Considerations for Doors and Fixtures: It's important to note that raising the floor level can affect door thresholds and other fixtures. Doors may need to be trimmed, and fixtures might need adjustments. :param insulation_floor_area: Area of the floor to be insulated :param material: Selected insulation material :param non_insulation_materials: Non-insulation materials required for the job :return: """ demolition_data = [x for x in non_insulation_materials if x["type"] == "solid_floor_demolition"] preparation_data = [x for x in non_insulation_materials if x["type"] == "solid_floor_preparation"] vapour_barrier_data = [x for x in non_insulation_materials if x["type"] == "solid_floor_vapour_barrier"] redecoration_data = [x for x in non_insulation_materials if x["type"] == "solid_floor_redecoration"] if ((len(demolition_data) != 1) or (len(preparation_data) != 2) or (len(vapour_barrier_data) != 1) or (len(redecoration_data) != 3)): raise ValueError("Incorrect number of data entries for non-insulation materials") # Break out the individual material costs preparation_material_costs = sum([x["material_cost"] * insulation_floor_area for x in preparation_data]) insulation_material_costs = material["material_cost"] * insulation_floor_area vapour_barrier_material_costs = vapour_barrier_data[0]["material_cost"] * insulation_floor_area redecoration_material_costs = sum([x["material_cost"] * insulation_floor_area for x in redecoration_data]) demolition_labour_costs = sum([x["labour_cost"] * insulation_floor_area for x in demolition_data]) preparation_labour_costs = sum([x["labour_cost"] * insulation_floor_area for x in preparation_data]) insulation_labour_costs = material["labour_cost"] * insulation_floor_area vapour_barrier_labour_costs = vapour_barrier_data[0]["labour_cost"] * insulation_floor_area redecoration_labour_costs = sum([x["labour_cost"] * insulation_floor_area for x in redecoration_data]) preparation_plant_costs = sum([x["plant_cost"] * insulation_floor_area for x in preparation_data]) labour_costs = (demolition_labour_costs + insulation_labour_costs + vapour_barrier_labour_costs + redecoration_labour_costs + preparation_labour_costs) labour_costs = labour_costs * self.labour_adjustment_factor materials_cost = (preparation_material_costs + insulation_material_costs + vapour_barrier_material_costs + redecoration_material_costs) subtotal_before_profit = labour_costs + materials_cost + preparation_plant_costs # We use HIGH_RISH_CONTINGENCY because of the potential for issues with moving fittings and trimming doors, # as well as scope for damage to the existing floor during preparation. contingency_cost = subtotal_before_profit * self.HIGH_RISK_CONTINGENCY preliminaries_cost = subtotal_before_profit * self.PRELIMINARIES profit_cost = subtotal_before_profit * self.PROFIT_MARGIN subtotal_before_vat = subtotal_before_profit + contingency_cost + preliminaries_cost + profit_cost vat_cost = subtotal_before_vat * self.VAT_RATE total_cost = subtotal_before_vat + vat_cost demolition_labour_hours = sum([x["labour_hours_per_unit"] * insulation_floor_area for x in demolition_data]) preparation_labour_hours = sum([x["labour_hours_per_unit"] * insulation_floor_area for x in preparation_data]) insulation_labour_hours = material["labour_hours_per_unit"] * insulation_floor_area vapour_barrier_labour_hours = vapour_barrier_data[0]["labour_hours_per_unit"] * insulation_floor_area redecoration_labour_hours = sum([x["labour_hours_per_unit"] * insulation_floor_area for x in redecoration_data]) labour_hours = (demolition_labour_hours + insulation_labour_hours + vapour_barrier_labour_hours + redecoration_labour_hours + preparation_labour_hours) # Assume a team of 3 people for a small to medium size project labour_days = (labour_hours / 8) / 3 return { "total": total_cost, "subtotal": subtotal_before_vat, "vat": vat_cost, "contingency": contingency_cost, "preliminaries": preliminaries_cost, "material": materials_cost, "profit": profit_cost, "labour_hours": labour_hours, "labour_days": labour_days, "labour_cost": labour_costs } def external_wall_insulation(self, wall_area, material, non_insulation_materials): """ We characterise external wall insulation as the following steps: 1) Preparation of the Area: Tidying up the surroundings, trimming back foliage, and laying down protective sheets to protect the flooring and landscaping around the work area. 2) Scaffolding Setup (if needed): Erecting scaffolding for safe access to the walls of semi-detached or detached houses. For terraced houses or lower-level work, scaffolding might not be necessary. 3) Wall Surface Preparation: Cleaning the wall surface, removing any loose or flaking material, and possibly applying a primer. If the existing wall is weak or damaged, partial or full replacement of the top surface may be necessary. 4) Applying Primer: If the existing wall is suitable, applying a primer to improve adhesion of the insulation boards and stabilize the wall surface, especially if it's old or weathered. 5) Insulation Application: Attaching insulation boards to the primed wall using adhesive, mechanical fixings, or a combination of both. 6) Basecoat and Mesh Application: Applying a basecoat embedded with a reinforcing mesh over the insulation. This layer provides strength and helps prevent cracking. 7) Decorative Finish: Applying a decorative finish, such as render or cladding, which protects the insulation and provides an aesthetic look. 8) Reinstalling Fixtures: Reattaching any fixtures like downpipes, satellite dishes, or lighting fixtures that were removed during preparation. Extensions or adjustments may be required due to the increased wall thickness. 9) Inspection and Cleanup: Conducting a thorough inspection to ensure quality and integrity of the EWI system, followed by cleaning up the site to remove all debris and materials. In the actual materials data, at this point, we have costing for: - wall preparation, hacking off existing wall finishes, linings, etc (ewi_wall_demolition) - wall surface cleaning and priming (ewi_wall_preparation) - insulation (external_wall_insulation) - basecoat and mesh with decorative render topcoat finish (ewi_basecoat_and_mesh) All of this data comes from SPONS, however there are some clear features missing. Because we could not find suitable cost records in SPONS for steps like cleaning the area, setting up small scale scaffolding, re-attaching any fitings and cleaning up the area afterwards, instead we have accounted for these steps by increasing the preliminaries rate. It is acknowldeged though, that this is not ideal and that the cost of these steps should be included in the materials data. We will look to improve this in the future, with data from installers :param wall_area: :param material: :param non_insulation_materials: :return: """ # For semi detatched and detatched houses, as well as maisonettes, we price for scaffolding if self.property.data["property-type"] == "House": if self.property.data["built-form"] in ['Semi-Detached', 'Detached', "End-Terrace"]: preliminaries_rate = self.EWI_SCAFFOLDING_PRELIMINARIES else: preliminaries_rate = self.EWI_NO_SCAFFOLDING_PRELIMINARIES elif self.property.data["property-type"] == "Maisonette": preliminaries_rate = self.EWI_SCAFFOLDING_PRELIMINARIES elif self.property.data["property-type"] == "Bungalow": preliminaries_rate = self.EWI_NO_SCAFFOLDING_PRELIMINARIES else: raise ValueError("Unsupported property type - haven't handled flats") demolition_data = [x for x in non_insulation_materials if x["type"] == "ewi_wall_demolition"] preparation_data = [x for x in non_insulation_materials if x["type"] == "ewi_wall_preparation"] redecoration_data = [x for x in non_insulation_materials if x["type"] == "ewi_wall_redecoration"] if (len(demolition_data) != 3) or (len(preparation_data) != 1) or (len(redecoration_data) != 1): raise ValueError("Incorrect number of data entries for non-insulation materials") # Break out the individual material costs # Since we don't know the exact wall construction, we take an average for demolition costs, since # the cost will depend on the type of wall construction demolition_material_costs = np.mean([x["material_cost"] * wall_area for x in demolition_data]) insulation_material_costs = material["material_cost"] * wall_area preparation_material_costs = preparation_data[0]["material_cost"] * wall_area redecoration_material_costs = redecoration_data[0]["material_cost"] * wall_area demolition_plant_costs = np.mean([x["plant_cost"] * wall_area for x in demolition_data]) demolition_labour_costs = np.mean([x["labour_cost"] * wall_area for x in demolition_data]) insulation_labour_costs = material["labour_cost"] * wall_area preparation_labour_costs = preparation_data[0]["labour_cost"] * wall_area redecoration_labour_costs = redecoration_data[0]["labour_cost"] * wall_area labour_costs = (demolition_labour_costs + insulation_labour_costs + redecoration_labour_costs + preparation_labour_costs) labour_costs = labour_costs * self.labour_adjustment_factor materials_costs = (demolition_material_costs + insulation_material_costs + preparation_material_costs + redecoration_material_costs) subtotal_before_profit = labour_costs + materials_costs + demolition_plant_costs contingency_cost = subtotal_before_profit * self.CONTINGENCY preliminaries_cost = subtotal_before_profit * preliminaries_rate profit_cost = subtotal_before_profit * self.PROFIT_MARGIN subtotal_before_vat = subtotal_before_profit + contingency_cost + preliminaries_cost + profit_cost vat_cost = subtotal_before_vat * self.VAT_RATE total_cost = subtotal_before_vat + vat_cost demolition_labour_hours = np.mean([x["labour_hours_per_unit"] * wall_area for x in demolition_data]) insulation_labour_hours = material["labour_hours_per_unit"] * wall_area preparation_labour_hours = preparation_data[0]["labour_hours_per_unit"] * wall_area redecoration_labour_hours = redecoration_data[0]["labour_hours_per_unit"] * wall_area labour_hours = (demolition_labour_hours + insulation_labour_hours + redecoration_labour_hours + preparation_labour_hours) # Assume a team of 3-5 people for a small to medium size project labour_days = (labour_hours / 8) / 4 return { "total": total_cost, "subtotal": subtotal_before_vat, "vat": vat_cost, "contingency": contingency_cost, "preliminaries": preliminaries_cost, "material": materials_costs, "profit": profit_cost, "labour_hours": labour_hours, "labour_days": labour_days, "labour_cost": labour_costs } def low_energy_lighting(self, number_of_lights, number_current_lel_lights, material): """ Calculates the total cost for low energy lighting based on material and labor costs, including contingency, preliminaries, profit, and VAT. :param number_of_lights: Int, number of light :param number_current_lel_lights: Int, number of low energy lights currently installed in the home :material: Dict, material data containing costs of fittings """ # If there are no lights fitted in the property, we increase the contingency in case there are potential wiring # blockers if number_current_lel_lights == 0: contingency = self.HIGH_RISK_CONTINGENCY else: contingency = self.CONTINGENCY material_cost = material["material_cost"] * number_of_lights labour_cost = material["labour_cost"] * number_of_lights * self.labour_adjustment_factor subtotal_before_profit = material_cost + labour_cost contingency_cost = subtotal_before_profit * contingency preliminaries_cost = subtotal_before_profit * self.PRELIMINARIES profit_cost = subtotal_before_profit * self.PROFIT_MARGIN subtotal_before_vat = subtotal_before_profit + contingency_cost + preliminaries_cost + profit_cost vat_cost = subtotal_before_vat * self.VAT_RATE total_cost = subtotal_before_vat + vat_cost labour_hours = material["labour_hours_per_unit"] * number_of_lights # Assume a single electrician installing labour_days = (labour_hours / 8) return { "total": total_cost, "subtotal": subtotal_before_vat, "vat": vat_cost, "contingency": contingency_cost, "preliminaries": preliminaries_cost, "material": material_cost, "profit": profit_cost, "labour_hours": labour_hours, "labour_days": labour_days, "labour_cost": labour_cost } def flat_roof_insulation(self, floor_area, material, non_insulation_materials): """ A model of a warm, flat roof construction can be seen in this video: https://www.youtube.com/watch?v=WZ6Ng6YI9OA Warm, flat roof insulation will normally be 100-125mm in depth We break this measure down into the following jobs to be done 1) Preparation of the room. This involves cleaning the existing roof surface, removing any debris and repairing any damage. Additionally, an edge barrier will likely need to be installed, to protect the sides of the roof from water ingress. 2) Primer Application. A layer of primer is applied to the clean roof surface to enhance the adhestia of subsequent layers, and seal the existing roof surface. 3) Vapour Proof Layer Installation. Lay a vapour control layer to prevent moisture ingress from inside the building, which is essential in warm roof construction. 4) Insulation Layer Application. Place and securely fix insulation boards over the roof. These could be rigid boards like PIR (Polyisocyanurate). 5) Waterproofing Membrane Installation: Cover the insulation (and timber layer, if used) with a waterproofing membrane, like EPDM, PVC, or bituminous felt. Carefully seal all joints, edges, and around any roof penetrations to ensure water tightness :param floor_area: Area of the flat roof to be insulated, based on the area of the floor :param material: Selected insulation material :param non_insulation_materials: Non-insulation materials required for the job :return: """ preparation_data_m2 = [ x for x in non_insulation_materials if (x["type"] == "flat_roof_preparation") and (x["cost_unit"] == "gbp_per_m2") ] vapour_barrier_data = [x for x in non_insulation_materials if x["type"] == "flat_roof_vapour_barrier"] waterproofing_data = [x for x in non_insulation_materials if x["type"] == "flat_roof_waterproofing"] if (len(preparation_data_m2) != 2) or (len(vapour_barrier_data) != 1) or ( len(waterproofing_data) != 1): raise ValueError("Incorrect number of data entries for non-insulation materials") # Break out the individual material costs preparation_m2_material_costs = sum([x["material_cost"] * floor_area for x in preparation_data_m2]) vapour_barrier_material_costs = vapour_barrier_data[0]["material_cost"] * floor_area insulation_material_costs = material["material_cost"] * floor_area preparation_m2_labour_costs = sum([x["labour_cost"] * floor_area for x in preparation_data_m2]) vapour_barrier_labour_costs = vapour_barrier_data[0]["labour_cost"] * floor_area # For waterproofing and upstand, we only have a total cost waterproofing_total_costs = waterproofing_data[0]["total_cost"] * floor_area labour_costs = preparation_m2_labour_costs + vapour_barrier_labour_costs labour_costs = labour_costs * self.labour_adjustment_factor materials_costs = preparation_m2_material_costs + vapour_barrier_material_costs + insulation_material_costs subtotal_before_profit = labour_costs + materials_costs + waterproofing_total_costs contingency_cost = subtotal_before_profit * self.FLAT_ROOF_CONTINGENCY preliminaries_cost = subtotal_before_profit * self.PRELIMINARIES profit_cost = subtotal_before_profit * self.PROFIT_MARGIN subtotal_before_vat = subtotal_before_profit + contingency_cost + preliminaries_cost + profit_cost vat_cost = subtotal_before_vat * self.VAT_RATE total_cost = subtotal_before_vat + vat_cost preparation_m2_labour_hours = sum([x["labour_hours_per_unit"] * floor_area for x in preparation_data_m2]) vapour_barrier_labour_hours = vapour_barrier_data[0]["labour_hours_per_unit"] * floor_area waterproofing_labour_hours = waterproofing_data[0]["labour_hours_per_unit"] * floor_area labour_hours = preparation_m2_labour_hours + vapour_barrier_labour_hours + waterproofing_labour_hours # To install flat roof insulation, assume a small/medium project might be conducted by a team of 2-4. # We'll assume a team of 2 since a lot of the roofs will be on the smaller side and will review this later labour_days = (labour_hours / 8) / 2 return { "total": total_cost, "subtotal": subtotal_before_vat, "vat": vat_cost, "contingency": contingency_cost, "preliminaries": preliminaries_cost, "material": materials_costs, "profit": profit_cost, "labour_hours": labour_hours, "labour_days": labour_days, "labour_cost": labour_costs } def window_glazing(self, number_of_windows, material, is_secondary_glazing=False): """ We characterise the jobs to be done for window glazing as the following: 1) Initial Assessment and Measurements: Before removing the existing window, it's essential to assess the condition of the window frame and opening. Precise measurements are taken to ensure the new double glazed windows fit perfectly. 2) Remove the Existing Window: This involves carefully dismantling and removing the old single glazed window. It requires skill to avoid damaging the surrounding wall and the window frame (if it's to be reused). 3) Dispose of the Existing Window: The old window, especially if it's a single glazed unit, needs to be disposed of responsibly. Glass and other materials should be recycled where possible. 4) Surface Preparation: The window opening might need some preparation, especially if there's damage or if adjustments are needed to accommodate the new window. This can include repairing or replacing parts of the window frame, sealing gaps, and ensuring the opening is level and square. 5) Install the Window Frame (if new frames are used): In many cases, double glazed windows come with their frames. These need to be installed securely into the window opening. This process involves aligning, leveling, and fixing the frame in place. 6) Install the Window Sill: If a new window sill is required, it is installed at this stage. It needs to be correctly aligned with the frame and securely attached. 7) Install the Double Glazed Glass Units: The glass units are carefully inserted into the frame. This step requires precision to ensure a snug fit without causing stress on the glass, which could lead to cracking or breaking. 8) Sealing and Weatherproofing: After the glass units are in place, it's crucial to seal around the frame and between the glass and frame to ensure there are no drafts and that the installation is weather-tight. This typically involves applying silicone sealant or other appropriate sealing materials. 9) Finishing Touches: This includes any cosmetic work, such as trimming, painting, or staining the frame and sill to match the rest of the property. It might also involve cleaning up any mess created during the installation. 10) Inspection and Testing: Finally, the new windows should be inspected to ensure they open, close, and lock correctly. This is also a good time to check for any gaps or issues with the sealing. For this cost estimation process, we factor in initial assement into the preliminaries """ material_cost = material["material_cost"] * number_of_windows labour_cost = ( material["labour_cost"] * number_of_windows * self.labour_adjustment_factor ) multiplier = self.SECONDARY_GLAZING_SCALING_FACTOR if is_secondary_glazing else ( self.SASH_WINDOW_INFLATION_FACTOR) subtotal = (material_cost + labour_cost) * multiplier contingency_cost = subtotal * self.CONTINGENCY preliminaries_cost = subtotal * self.PRELIMINARIES profit_cost = subtotal * self.PROFIT_MARGIN subtotal_before_vat = subtotal + contingency_cost + preliminaries_cost + profit_cost vat_cost = subtotal_before_vat * self.VAT_RATE total_cost = subtotal_before_vat + vat_cost labour_hours = material["labour_hours_per_unit"] * number_of_windows labour_hours = labour_hours * self.SECONDARY_GLAZING_SCALING_FACTOR if is_secondary_glazing else labour_hours # Assume a team of 2 labour_days = (labour_hours / 8) / 2 return { "total": total_cost, "subtotal": subtotal_before_vat, "vat": vat_cost, "contingency": contingency_cost, "preliminaries": preliminaries_cost, "material": material_cost, "profit": profit_cost, "labour_hours": labour_hours, "labour_cost": labour_cost, "labour_days": labour_days } def solar_pv(self, wattage: float, has_battery: bool = False): """ Calculates the total cost for solar PV based data provided by the MCS dashboard, which contains costing data for installations of renewable and clean energy measures. The data in the dashboard is filtered on domestic building installations and then the data across the various regions is manually collected. There is currently no automated way to get the data from the MCS dashboard Price can also be benchmarked against this checkatrade article: https://www.checkatrade.com/blog/cost-guides/cost-of-solar-panel-installation/ :param wattage: Peak wattage of the solar PV system] :param has_battery: Bool, whether the system includes a battery """ # Get the cost data relevant to the region regional_cost = MCS_SOLAR_PV_COST_DATA["-".join(["average_cost_per_kwh", self.region])] kw = wattage / 1000 total_cost = kw * regional_cost if has_battery: # The battery cost is based on the £3500 quote, recieved from installers total_cost += BATTERY_COST subtotal_before_vat = total_cost / (1 + self.VAT_RATE) vat = total_cost - subtotal_before_vat # Labour hours are based on estimates from online research but an average team seems to consist of 3 people # and most jobs take around 2 days. Assuming an 8 hour day for 3 people across 2 days, gives us 72 hours of # labour return { "total": total_cost, "subtotal": subtotal_before_vat, "vat": vat, "labour_hours": 72, "labour_days": 2, } def programmer_and_appliance_thermostat(self, has_programmer): """ Calculate the total cost of installing a programmer and appliance thermostat If the property already has a programmer, then the only thing we need to calculate the cost for is the appliance thermostat """ if has_programmer: labour_hours = 2 total_cost = SMART_APPLIANCE_THERMOSTAT_COST else: labour_hours = 4 total_cost = SMART_APPLIANCE_THERMOSTAT_COST + PROGRAMMER_COST subtotal_before_vat = total_cost / (1 + self.VAT_RATE) vat = total_cost - subtotal_before_vat # We estimate the cost of an appliance thermostat at £400, which is the upper end of the range return { "total": total_cost, "subtotal": subtotal_before_vat, "vat": vat, "labour_hours": labour_hours, "labour_days": 1, } def electric_room_heaters(self, number_heated_rooms): """ We base the estimates for the cost of electric room heaters on the cost per room as estimated by the following article: https://www.bestelectricradiators.co.uk/blog/cost-to-install-a-new-heating-system-uk/ :param number_heated_rooms: int, number of rooms to be heated :return: """ total_cost = 500 * number_heated_rooms subtotal_before_vat = total_cost / (1 + self.VAT_RATE) vat = total_cost - subtotal_before_vat # TODO: Rough estimate to be reviewed labour_hours = 1 * number_heated_rooms labour_days = np.ceil(labour_hours / 8) return { "total": total_cost, "subtotal": subtotal_before_vat, "vat": vat, "labour_hours": labour_hours, "labour_days": labour_days, } def high_heat_electric_storage_heaters(self, number_heated_rooms): """ We base the estimates for the cost of electric storage heaters on the cost per room as estimated by the energy saving trust https://energysavingtrust.org.uk/advice/electric-heating/ The cost is based on the number of heated rooms :param number_heated_rooms: int, number of rooms to be heated """ total_cost = 1500 * number_heated_rooms subtotal_before_vat = total_cost / (1 + self.VAT_RATE) vat = total_cost - subtotal_before_vat # TODO: Rough estimate to be reviewed labour_hours = 3 * number_heated_rooms labour_days = np.ceil(labour_hours / 8) return { "total": total_cost, "subtotal": subtotal_before_vat, "vat": vat, "labour_hours": labour_hours, "labour_days": labour_days, } def celect_type_controls(self): """ Calculate the cost of installing Celect type controls """ # The £50 cost is a rough estimate based on internet research total_cost = 50 subtotal_before_vat = total_cost / (1 + self.VAT_RATE) vat = total_cost - subtotal_before_vat # We estimate the labour hours to be 4 return { "total": total_cost, "subtotal": subtotal_before_vat, "vat": vat, "labour_hours": 4, "labour_days": 1, } def hot_water_tank_insulation(self): """ Calculate the cost of installing hot water tank insulation """ # The £50 cost is a rough estimate based on internet research total_cost = 50 subtotal_before_vat = total_cost / (1 + self.VAT_RATE) vat = total_cost - subtotal_before_vat return { "total": total_cost, "subtotal": subtotal_before_vat, "vat": vat, "labour_hours": 0, "labour_days": 0, } def roomstat_programmer_trvs( self, number_heated_rooms, has_programmer, has_trvs, has_room_thermostat ): """ :return: """ total_cost = 0 labour_hours = 0 if not has_programmer: total_cost += PROGRAMMER_COST labour_hours += 1 if not has_trvs: total_cost += TRVS_COST * number_heated_rooms labour_hours += 0.25 * number_heated_rooms if not has_room_thermostat: total_cost += ROOM_THERMOSTAT_COST labour_hours += 0.5 subtotal_before_vat = total_cost / (1 + self.VAT_RATE) vat = total_cost - subtotal_before_vat return { "total": total_cost, "subtotal": subtotal_before_vat, "vat": vat, "labour_hours": labour_hours, "labour_days": 1, } def time_and_temperature_zone_control(self, number_heated_rooms): # The product costs are inclusive of VAT product_costs = ( TTZC_SMART_THERMOSTAT_COST + TTZC_ROOM_TEMPERATURE_SENSOR_COST * number_heated_rooms + TTZC_SMART_RADIATOR_VALUES * number_heated_rooms ) labour_hours = ( TTZC_SMART_THERMOSTAT_LABOUR_HOURS + TTZC_ROOM_TEMPERATURE_SENSOR_LABOUR_HOURS * number_heated_rooms + TTZC_SMART_RADIATOR_VALUES_LABOUR_HOURS * number_heated_rooms ) labour_costs = TTZC_ELECTRICIAN_HOURLY_RATE * labour_hours # Add continency and preliminaries to the labour to account for the complexity of the job labour_costs = labour_costs * (1 + self.CONTINGENCY + self.PRELIMINARIES) vat = labour_costs * self.VAT_RATE subtotal_before_vat = product_costs + labour_costs total_cost = subtotal_before_vat + vat labour_days = np.ceil(labour_hours / 8) return { "total": total_cost, "subtotal": subtotal_before_vat, "vat": vat, "labour_hours": labour_hours, "labour_days": labour_days, } def low_carbon_boiler(self, is_combi, size): """ Based on a basic estimate of median value £2600 to install a low carbon combi boiler :return: """ unit_cost = COMBI_BOILER_COSTS[size] if is_combi else CONVENTIONAL_BOILER_COSTS[size] # The unit cost is the cost without VAT # We now need to estimate the cost of the works labour_days = 2 labour_rate = 500 # Average cost of installation is 1 (maybe 2days) at £300 per day # https://www.checkatrade.com/blog/cost-guides/new-boiler-cost/ # To be pessimistic, assume 2 days work and £500 day rate labour_cost = labour_rate * self.labour_adjustment_factor * labour_days # Add contingency and preliminaries labour_cost = labour_cost * (1 + self.CONTINGENCY + self.PRELIMINARIES) vat = labour_cost * self.VAT_RATE subtotal_before_vat = unit_cost + labour_cost total_cost = subtotal_before_vat + vat return { "total": total_cost, "subtotal": subtotal_before_vat, "vat": vat, "labour_hours": labour_days * 8, "labour_days": labour_days, }