SAP calculations in Haringey

Heritage across Haringey

The borough has 33 conservation areas, 289 listed entries and 4 registered parks and gardens. Of the listed entries, 21 are Grade II*, and 21 entries sit on the Heritage at Risk Register.

The calculation can change street by street. A Victorian terrace in a conservation area may keep its sash windows, which lowers glazing performance, so the roof and floor have to compensate. A modern house a few streets away has no such limit and can use a standard high-performance window.

Two housing markets, two energy strategies

A terraced house in Haringey averaged £803,381 in the latest Land Registry data, but a detached house reached £2,460,369. Only 38.9 per cent of households live in a house, and 37.2 per cent own their home.

For terraces we keep to simple limits and a tidy specification. On the large detached houses the money is available for a full SAP model, a heat pump and a design with generous glazing, and the model shows how far each choice moves the result.

What the extension rules say

New elements must meet the following: New elements in existing dwellings, limiting U-values W/(m²·K): roof 0.15, wall 0.18, floor 0.18, windows 1.4 (or WER Band B), doors 1.4. A dormer cheek wall or a loft roof is a new element, so loft work is held to the same table.

Glazing is capped on the simple route: Windows, roof windows, rooflights and doors in an extension should not exceed 25% of the extension floor area plus the area of openings removed or covered. If a rear glass wall breaks the cap, the alternatives are: Alternative routes: area-weighted U-value (para 10.9) or a SAP calculation against a notional extension (para 10.10).

Our dormer loft conversion drawings apply the same table to roof windows, which count as glazing.

New homes in Haringey and the move to a new method

Infill houses and flat conversions are assessed as new dwellings. For new dwellings AD L 2026 names two methods: the Home Energy Model (HEM) and SAP; validity dates are in the Notice of Approval. Which edition applies depends on your deposit date: AD L/F 2021 continue where plans/notices are deposited before 24 Mar 2027 and work starts before 24 Mar 2028.

Because the borough's flats often sit in dense streets, summer comfort comes up too: Approved Document O (overheating) applies to new residential buildings. The assessor needs the orientation, the window areas and any shading from neighbours.

A practical order of work for Haringey homes

Start with the constraints check, which tells you which guidance applies and whether the street has any designation. Then fix the footprint with planning in mind. Only then is it worth running the energy figures, because a change in size alters everything beneath it.

Next, choose the heating. Many homes still run on gas boilers, and a switch to a heat pump changes the insulation the design needs. We ask the assessor to model both and show the result side by side.

Finally, fix the glazing and run the final model. The report goes into the building regulations package with the drawings, and the same reference numbers appear on both so the officer can follow the chain without calling us.

If you are unsure where your house sits against the local guidance, send the postcode and we will tell you before any fee is agreed. That check is free and takes a short time.

Where this sits in your Haringey drawings

For the planning side, see architectural drawings in Haringey. For the technical sheets, see building regulations drawings in Haringey, and for the beams see structural calculations in Haringey.

The energy work is a fixed quote after a free constraints check, VAT included. Send the address and tell us which part of the borough it is in.