- Postcode district
- SW12
- Survey
- Free for new and replacement doors
- Typical lead time
- Typically 6–8 weeks for slimline systems after check survey sign-off
- Guide price
- From £5,095 inc VAT
- Nearby
- Tooting, Streatham, Clapham
- Building rules
- England
What sliding doors for extensions offer homes in Balham
A few practical points decide whether sliding doors for extensions suit a particular room and opening:
Planning an extension in Balham? Send us the drawings before the steel is ordered, so the beam above the doors can be designed with the door in mind.
If your Balham builder is about to pour the screed, confirm the finished floor level for the threshold first, because it is very hard to change afterwards.
- Being involved at drawing stage means the opening is formed to suit the door, rather than the door being compromised to suit an opening built a few centimetres out.
- A check survey once the opening is built means the door is made to the real dimensions, accounting for any small variation in the brickwork or blockwork.
- Garden rooms benefit from the same approach, with a door sized to the frame and a header designed to carry the roof without pressing down on the door.
Light and sun in Balham
At the latitude of Balham, the midday sun climbs to about 62° in late June but only about 15° in late December, when daylight lasts around 7 h 50 min against 16 h 38 min in midsummer. A south-facing sliding door for an extension lets that low winter sun deep into the room; on a west or south elevation, solar-control glass keeps summer afternoons comfortable.
Guide prices for sliding doors for extensions in Balham
Guide prices are the same across Greater London. They cover the door supplied and fitted into a prepared opening, including VAT, with options itemised in your quote.
| Overall width | Typical panels | Guide price (fitted, inc VAT) |
|---|---|---|
| 2.1 m | 2 panels | £5,495–£6,795 |
| 3.6 m | 2 panels | £7,795–£9,495 |
| 4.0 m | 3 panels | £8,395–£10,195 |
See every size on the sliding doors for extensions page or try the guide price tool.
How fitting works in Balham
Nothing is ordered until you sign off the surveyed specification. The door is made from the finished opening sizes (typically 6–8 weeks for slimline systems after check survey sign-off), and fitting usually takes 1–2 days, scheduled to the build programme. If you are in Tooting or Streatham, the same process and prices apply.
Rules for sliding doors for extensions in England
Doors in an English extension go through the extension's Building Regulations approval. Under Approved Document L, the total area of windows, roof windows and doors is normally capped at 25% of the extension's floor area plus any openings the extension removes, unless your designer shows compensating improvements; the glass must be safety glazing under Approved Document K.
Specification choices for sliding doors for extensions in Balham
- Flush threshold. A level floor from inside to out, with a drainage channel set into the patio.
- Triple glazing. For low-energy extensions or north-facing walls, subject to panel size limits.
- Corner opening. Sliding panels meeting at a corner with no post, for extensions open on two sides.
Questions about sliding doors for extensions in Balham
How soon can you survey in Balham?
Surveys in the SW12 district are booked at a time that suits you, and we offer survey dates when we reply to your enquiry. After you approve the written quote, manufacture is typically 6–8 weeks for slimline systems after check survey sign-off.
How do I get a level threshold in an extension?
A level or flush threshold in an extension needs the finished floor level inside to be set relative to the door sill and the outside paving before the screed goes down. Outside, a drainage channel is needed across the threshold so rain cannot run in. Our thresholds guide explains the options.
Can you measure from drawings rather than the built opening?
We can quote from drawings, but we manufacture from a check survey of the built opening, because real openings often differ slightly from the plans. Making a large made-to-measure door from drawings alone risks it not fitting. If a programme makes that unavoidable, any arrangement and who carries the risk would be agreed in writing first.
What sliding doors suit a garden room?
A garden room usually suits a two-panel or three-panel sliding door sized to the front of the building, with a header strong enough to carry the roof without pressing on the frame. Aluminium systems are a common choice because they are stable and need little maintenance. Glass with good insulation helps if the room will be used all year.