Low Energy Buildings Database

RetroPHit -03 PRE-CAST CONCRETE HOUSE, HEREFORD CITY. : Project images

Click on image to preview full size

Energy and fuel use

Fuel use

	Pre-development	Forecast	Measured
Electricity use	3300 kWh/yr	-	-
Natural gas use	18500 kWh/yr	-	-
Oil use	-	-	-
LPG use	-	-	-
Wood use	-	-	-
Other Fuel	-	-	-

	Pre-development	Forecast	Measured
Primary energy requirement	404 kWh/m².yr	-	-
Annual CO₂ emissions	79 kg CO₂/m².yr	-	-
Annual space heat demand	-	-	-

Renewable energy

Electricity generation	Forecast	Measured
Renewables Technology	-	-
Other Renewables Tech	-	-
Electricity consumed by generation	-	-
Primary energy requirement offset by renewable generation	-	-
Annual CO₂ emissions offset by renewable generation	-	-

Calculation and targets

Whole house energy calculation method
Other whole house calculation method	-
Energy target
Other energy targets	-
Forecast heating load	-

Airtightness

	Date	Result
Pre-development air permeability test	-	-
Final air permeability test	-	-

Project description

Stage	Conception
Start date
Occupation date
Location	Herefordshire  England
Build type	Refurbishment
Building sector	Public Residential
Property type	Semi-Detached
Construction type	Concrete frame
Other construction type
Party wall construction
Floor area	73 m²
Floor area calculation method	Treated Floor Area (PHPP)
Building certification

Project Team

Organisation	RetroPHit
Project lead person	RetroPHit
Landlord or Client	LEAF
Architect	Simmonds.Mills
Mechanical & electrical consultant
Energy consultant	EAA
Structural engineer
Quantity surveyor
Consultant
Contractor

Design strategies

Planned occupancy	Standard (2.1)
Space heating strategy	URBAN (1) Natural gas Heat source: balanced flue natural gas-fired condensing boiler. To be located within the heated space wherever possible. Emitters: new or existing radiators, sized for low-temperature operation, with maximum flow/return temperatures on a design day of 60/40 degC, assuming continuous heating Radiators to use top-bottom opposite end (TBOE) connection. Pipes: No heating pipes to be run in loft, ground floor or buried in external walls; i.e., they must be within the thermal envelope. Pipes can be concealed within timber first floors if appropriate. Insulation: heating pipework to be insulated, except exposed radiator tails.System control: Weather-compensation controls to regulate the flow temperature as a function of the outside temperature. Other system controls to be chosen on a project-by-project basis. DHW system: tank-in-tank type heat exchanger. Tank insulation to be minimum 100 mm PU foam ( = 0.025 W/mK) or equiv. Tank to be as close as possible, ideally within kitchen(s) and/or bathroom(s), where the largest number of DHW uses occur. Choose a compact plumbing system if the building is being extensively refurbished/remodelled. Measures to reduce the risk of legionella disease.
Water heating strategy	see above
Fuel strategy	natural gas
Renewable energy strategy	none
Passive Solar strategy
Space cooling strategy
Daylighting strategy	Daylighting strategies: improve daylighting levels by paint interiors lighter colours, when replacing or reglazing windows e.g., by reducing mullion & transom area, etc
Ventilation strategy	MEV. For a building that can be draughtproofed to a level at least twice as good as current building regulations; i.e. 5 ac/h @ 50 Pa then as long as there are no open-flued combustion appliances then 'Whole building Mechanical Extract Ventilation' (MEV) can be considered . This option does not normally recover any heat from the extracted air, but does yield consistent air quality and steady, predictable ventilation. It also almost eliminates the heat loss due to the draughts in a normal building. Air supply can be either via existing trickle vents (not in rooms where the MEV extracts from - these are closed off) or for improved comfort through the wall air inlets can be fitted (passive; i.e., not powered) behind or near radiators to prewarm the fresh incoming air.
Airtightness strategy	Urban house: retrofit air permeability target of 3.0 m3/m2hr@50 Pa
Strategy for minimising thermal bridges
Modelling strategy
Insulation strategy	Cavity wall or concrete panel where external leaf treated as 'solid wall' for EWI: External Wall Insulation . Air-seal cavity if leakage evident - horizontally at eaves/verges & wall to foundation junction. Measures may be needed at party walls.Air pressure test equipment to be used during works.Solid conc. slab on ground: Draughtproof edges of slab to wall inner leaf. Suggests skirting board renewal. Perimeter insulation.Timber Roof: Option involving renewal of internal linings - Maintain ventilation between rafters and add insulation and vapour control internally.Option involving renewal of lower section of mansard roof tiles - min. fibre and PU foam as air barrier, or all PU foam.Attic Floor: Timber - Remove quilt insulation. Vaccuum floor and raise wiring if neccessary. Air seal leaks in attic floor areas. Top up with quilt insulation. Insulate all walls facing heated spaces and 1.0m up gable walls. Ensure attic ventilation.Horizontal insulation levels c. 400mm deep. Vertical areas either 50 - 100mm spray foam or 100-150mm quilt between battens/studs (EWI style).
Other relevant retrofit strategies
Contextual information

Building services

Occupancy
Space heating
Hot water
Ventilation
Controls
Cooking
Lighting
Appliances
Renewable energy generation system
Strategy for minimising thermal bridges

Building construction

Storeys
Volume	-
Thermal fabric area	-
Roof description
Roof U-value	-
Walls description
Walls U-value	-
Party walls description
Party walls U-value	-
Floor description
Floor U-value	-
Glazed doors description
Glazed doors U-value	- -
Opaque doors description
Opaque doors U-value	- -
Windows description
Windows U-value	- -
Windows energy transmittance (G-value)	-
Windows light transmittance	-
Rooflights description
Rooflights light transmittance	-
Rooflights U-value	-