Refurbishment sequence
Rendering as Part of a Larger House Refurbishment
Rendering often comes near the end of a refurbishment, but the decisions that shape it come much earlier. New windows set the reveals and sills, roofline work sets the top edge, meters and pipes have to be in their final places, and an insulation decision changes the thickness of the whole wall. Get the order right and the render goes on once.
On this page
The order of work
As a rule, anything that is fixed into or through the wall goes in before the final render. New windows and doors come first, so the render can finish to their frames and their sills can be sized to project beyond the new face. Roofline work, such as new fascias, soffits or gutters, comes before the top of the wall is rendered, so flashings and edges lap correctly. Meter boxes, outside lights, vents, cables and taps go in their final positions before the base coat.
Then the walls are stripped, repaired and rendered, and the downpipes are refitted last. Landscaping and paving follow, kept below the bead at the base of the wall so the DPC is not bridged.
External insulation changes the sequence. INCA's guidance is that new windows should be installed before the insulation and sized so their sills overhang the finished face by at least 40mm. A commercial project would set that out on drawings; on a house, the same principle applies to a short list agreed between the trades.
| Stage | Why before the render |
|---|---|
| Windows and doors | Render finishes to frames; sills sized to the new face |
| Roofline and gutters | Flashings and top edges lap over the render |
| Services through the wall | No cutting into finished render later |
| Insulation decision | Sets wall thickness, sills and eaves |
| Downpipes and paving | Refitted and laid after render, below the bead |
The insulation question
If a large refurbishment includes re-rendering most of the walls, building regulations may expect the walls to be insulated at the same time. Approved Document L treats rendering the outside of a wall as renovation, and where more than half of a wall, or more than a quarter of the whole envelope, is renovated it expects an upgrade to 0.30 W/m²K where that is technically, functionally and economically feasible. Raise it with building control before ordering windows, because external insulation needs deeper sills and may need the roofline extended.
The commercial and new-build page covers coordination on larger jobs, and the external wall insulation guide explains the boards, mesh and details involved.
Samples and late changes
Choose the render colour once the window frames, roof covering and any retained brick are settled, because a colour that worked against white frames may not work against grey ones. A sample panel on the wall, viewed beside the new materials, is the reliable test.
Late changes cost render time. A pipe moved after the base coat means cutting and patching; a sill changed after the finish means making good around it. Keep one current drawing or list of what goes where on each wall, and give the renderer any change before the coats go on.
Allow time for the render's own programme within the larger one. A base coat that has to cure for a fortnight before a silicone finish, or lime coats a week apart, can hold up other outside trades if nobody planned for it. Agree which trades can work on the scaffold while coats are curing, and which must wait until the render is finished and protected.
What happens when the order is wrong
The commonest mistake is rendering before the windows are replaced. New frames are rarely the same depth as old ones, so the reveals are cut back, the sills changed and the render patched round every opening, and patches in a through-coloured render seldom match. The second is fitting new fascias and gutters after the render, which leaves brackets and downpipe fixings drilled through the new face and flashings that no longer lap correctly.
Services are the third. A meter box moved after the base coat, a new boiler flue cut through the finished render, or cables run across the wall surface all leave scars. And landscaping done last but carelessly can bury the bell-cast bead under raised paving, bridging the DPC the render was designed to stay clear of.
For example, on a hypothetical 1950s house being fully refurbished, a workable order would be: roof and new fascias and gutters; new windows and doors with sills sized for the finished wall; electrician and plumber to fix meter box, lights, taps and flue in final positions; stripping, repairs and render; downpipes refitted; then paths and patio laid at least below the bead. Each trade then works once, on a wall that is ready for it.
Handover
When the trades finish, walk round with the list and check each junction: render to frames, render to sills, the top edge under the eaves, the base above the DPC and every pipe and fitting refixed. Keep the window, roofline and render details together with photographs taken before the walls were covered.
Give the house file the product names and colour references for the render. The Doncaster rendering homepage links the individual services, so the record can show which work each wall received.
Common questions
Who should keep the final exterior documents?
You should, as the person who commissioned the work. Each trade may keep its own records, but the house needs one set showing the windows, roofline, render system, colours and any insulation, with the latest drawings marked as final. That file is what a future buyer, surveyor or repairer will ask for.
Should the render go on before or after the roof is replaced?
After, as a rule. Roof work can damage fresh render with dropped materials, and new fascias, soffits and gutters set the top edge the render should finish against. If the roof has to wait, agree how the eaves will be protected and finished so the render does not need cutting back later.
Does every refurbishment that includes rendering need building control?
Not every one, but re-rendering most of a wall can count as renovating it under Approved Document L, and external insulation always changes the wall. Ask building control at the planning stage, because their answer can change the window and roofline details as well as the render.
Can the render colour be chosen before the windows are ordered?
You can shortlist colours early, but make the final choice with a sample beside the actual frames, sills and roof covering. A render that looked right on a chart beside white frames may look quite different next to dark grey ones.
See housing and planning information for Doncaster and nearby places, including the source and geography behind each figure.
