One Planet Sutton Retrofit
Download
as PDF The project aim is to design a specification to retrofit three typical local authority owned houses and to model the associated carbon savings from a range of opportunities from material choice and operational efficiency to the carbon impacts of tenants' lifestyles. The whole house carbon reduction measures proposed for a "One Planet House" have been selected following an analysis of costs, practicality and embodied carbon to achieve a total fabric heat loss to meet a post retrofit target of 16.9kgCO2/m2. The One Planet House will be compared with a Decent Homes plus CERT funded refurbishment and with those from an unimproved home. The savings due to changes in occupant behaviour will also be monitored in all three houses.
Retrofit for the future ZA122S
One Planet Sutton Retrofit : Project images
Click on image to preview full size
Energy and fuel use
Measured data from renewable generation is not yet available.
Fuel use
| Pre-development | Forecast | Measured | |
| Electricity use | 4646 kWh/yr | 2515 kWh/yr | - |
|---|---|---|---|
| Natural gas use | 12951 kWh/yr | 3417 kWh/yr | - |
| Oil use | - | - | - |
| LPG use | - | - | - |
| Wood use | - | - | - |
| Other Fuel | - | - | - |
| Pre-development | Forecast | Measured | |
| Primary energy requirement | 360 kWh/m².yr | 139 kWh/m².yr | - |
|---|---|---|---|
| Annual CO₂ emissions | 73 kg CO₂/m².yr | 30 kg CO₂/m².yr | - |
| Annual space heat demand | 177 kWh/m².yr | 41.7 kWh/m².yr | - |
Renewable energy
| Electricity generation | Forecast | Measured |
|---|---|---|
| Solar PV | 1492 kWh/yr | - |
| Other Renewables Tech | - | - |
| Electricity consumed by generation | - | - |
| Primary energy requirement offset by renewable generation | 88 kWh/m².yr | - |
| Annual CO₂ emissions offset by renewable generation | 18 kg CO₂/m².yr | - |
Calculation and targets
| Whole house energy calculation method | OTHER |
|---|---|
| Other whole house calculation method | The Parity Projects Domestic Renovation Energy Model uses data about building characteristics and resident behaviour to derive a |
| Energy target | Retrofit for the Future |
| Other energy targets | - |
| Forecast heating load | 4.76 W/m² demand |
Airtightness
| Date | Result | |
| Pre-development air permeability test | - | - |
|---|---|---|
| Final air permeability test | - | - |
Project description
| Stage | Design (planning permission granted) |
|---|---|
| Start date | 29 November 2010 |
| Occupation date | 31 January 2011 |
| Location | Carshalton Surrey England |
| Build type | Refurbishment |
| Building sector | Public Residential |
| Property type | Mid Terrace |
| Construction type | Masonry Cavity |
| Other construction type | 50 mm filled cavity |
| Party wall construction | 230mm solid brick |
| Floor area | 73.7 m² |
| Floor area calculation method | Actual Floor Area (SAP) |
| Building certification |
Project Team
| Organisation | BioRegional Consulting Ltd |
|---|---|
| Project lead person | BioRegional Consulting Ltd |
| Landlord or Client | Sutton Housing Partnership |
| Architect | |
| Mechanical & electrical consultant | |
| Energy consultant | Parity Projects |
| Structural engineer | |
| Quantity surveyor | |
| Consultant | |
| Contractor | Lakehouse |
Design strategies
| Planned occupancy | Three people all out to work or school during the day. At home most evenings and at weekends. |
|---|---|
| Space heating strategy | Heating from mains gas fired boiler feeding radiators. System is properly balanced using thermostatic radiator valves and programmed to optimally meet the residents' needs. Heat is recovered from ventilation exhaust in the kitchen and bathroom. |
| Water heating strategy | Solar hot water (with gas condensing boiler back up). No electric resistance heating back-up. |
| Fuel strategy | Mains Gas. Mains electricity with solar photovoltaic array. |
| Renewable energy strategy | 1.8kWp photovoltaic array to be installed and to be grid connected. 8m2 of glazed flat plate solar thermal to be installed. Both systems were selected to enable side by side performance monitoring of the two systems. |
| Passive Solar strategy | No changes are envisaged to increase passive solar gains or daylight factors. The front of the house, with the main living room and bedroom, faces south so that the main habitable spaces benefit directly from passive solar gain. |
| Space cooling strategy | Natural ventilation using openable windows in the habitable rooms for most of the summer months. In addition secure background ventilation, when the rooms are not occupied, is provided by the 'trickle vents' in the new windows. |
| Daylighting strategy | The houses were originally designed and built to meet public health by-laws that required suitable sized windows to each of the habitable rooms to achieve adequate daylight and so no additional daylighting provision is proposed. |
| Ventilation strategy | Individual heat recovery units provide supply and extract ventilation in the kitchen and bathroom to remove moisture generated at source. The new windows are supplied with 'trickle vents' that provide controllable and secure 'background ventilation' to all habitable rooms, particularly during the winter, to remove moisture and other pollutants to ensure adequate indoor air quality. 'Rapid ventilation' is provided through openable windows. |
| Airtightness strategy | The main structural air leakage routes will be identified during the pre-retrofit air-tightness testing. All visible gaps and the identified major leakage routes will be sealed up, the extractor fans in the kitchen and bathroom will be replaced with heat recovery units and redundant flues will be sealed using 'chimney balloons'. The replacement windows and internal insulation will be installed and sealed by trained operatives and service entries through the external walls and ceilings will be properly sealed. The suspended timber ground floor will be sealed after the insulation has been installed between the floor joists. An air leakage rate of 0.5 air changes/hour under normal conditions is estimated. |
| Strategy for minimising thermal bridges | Continuous insulation maintained throughout, cavity wall insulation continuous with adjoining houses. Installation by trained operatives and supervised to ensure continuity achieved in practice. |
| Modelling strategy | Whole housing modelling undertaken in PHPP, SAP and using Parity Projects Domestic Renovation Energy Model. The Parity Projects model was used for detailed evaluation as it could be tailored to the residents' actual lifestyle and calibrated against their bills. |
| Insulation strategy | 50mm Pavatherm internally to cavity filled external walls (u = 0.24) at the front of house. Rear bathroom pod upgraded to Decent Homes standard (u value = 0.22) . Vertical 100mm edge insulation (PIR) to kitchen solid ground floor (u = 0.38). 70mm of PIR insulation to exterior of rear wall. 100mm Pavatherm insulation between suspended ground floor joists (u = 0.12). Topping up loft insulation to 300mm with cellulose (warmcell) insulation (u = 0.13). High performance timber framed double glazed windows and thick curtains (u = 1.38). High performance external doors (u = 1.81 and 1.78) |
| Other relevant retrofit strategies | We are planning to carry out our package of retrofit measures with tenants remaining in the dwelling during the proposed works. We intend to demonstrate our approach can be undertaken with minimal disruption to the tenants and with no associated temporary re-housing costs. However, the budget allows for the tenants to have a week's holiday while the suspended ground floor is insulated if required. For the 'One Planet House' we have selected local (UK manufactured for most) and sustainable materials using an embodied CO2 analysis that showed that very high levels of thermal performance could be achieved for about half of the embodied CO2 of standard 'Decent Homes' insulation measures, saving 0.5t of embodied CO2. |
| Contextual information |
Building services
| Occupancy | NULL |
|---|---|
| Space heating | NULL |
| Hot water | NULL |
| Ventilation | NULL |
| Controls | NULL |
| Cooking | NULL |
| Lighting | NULL |
| Appliances | NULL |
| Renewable energy generation system | NULL |
| Strategy for minimising thermal bridges | NULL |
Building construction
| Storeys | |
|---|---|
| Volume | - |
| Thermal fabric area | - |
| Roof description | NULL |
| Roof U-value | 0.00 W/m² K |
| Walls description | NULL |
| Walls U-value | 0.00 W/m² K |
| Party walls description | NULL |
| Party walls U-value | 0.00 W/m² K |
| Floor description | NULL |
| Floor U-value | 0.00 W/m² K |
| Glazed doors description | NULL |
| Glazed doors U-value | 0.00 W/m² K - |
| Opaque doors description | NULL |
| Opaque doors U-value | 0.00 W/m² K - |
| Windows description | NULL |
| Windows U-value | 0.00 W/m² K - |
| Windows energy transmittance (G-value) | - |
| Windows light transmittance | - |
| Rooflights description | NULL |
| Rooflights light transmittance | - |
| Rooflights U-value | 0.00 W/m² K |