- Postcode district
- WD7
- 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
- St Albans, Edgware, Barnet
- Building rules
- England
Is a sliding door for an extension a good fit for your home in Radlett?
Most homeowners choosing sliding doors for extensions want the same things: more light, a clear view and a door that is easy to live with.
Self-building in Radlett or elsewhere in Hertfordshire? Ask for the sliding doors to be quoted as part of a wider glazing package so the frames, colours and glass match across the house.
When your Radlett extension is going through Building Control, keep the energy information for the doors to hand, as the inspector may ask for it.
- Slimline aluminium systems with interlocks typically around 20–25 mm maximise the glass in a new rear wall, keeping the view as open as possible.
- 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 Radlett
The midday sun over Radlett ranges from about 15° at the winter solstice to about 62° at midsummer. Low-angle winter light reaches further into a room through a tall door, which is one reason taller panels are worth considering; on south or west walls, pair them with solar-control glass.
Typical costs for sliding doors for extensions around Radlett
Guide prices are the same across Hertfordshire. 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 |
| 2.4 m | 2 panels | £5,995–£7,295 |
| 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.
From survey to fitted door in Radlett
Surveys in the WD7 district are booked at a time that suits you. Once the opening is ready and measured, manufacture is typically 6–8 weeks for slimline systems after check survey sign-off; on fitting day the frame is set level and sealed, and the panels are adjusted so they glide properly. Fitting usually takes 1–2 days, scheduled to the build programme.
Do you need approval in Radlett?
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.
Which options matter for sliding doors for extensions?
- Solar-control glass. Coated glass for south- and west-facing extensions prone to summer overheating.
- Two-panel slimline. One sliding and one fixed panel, suiting openings up to around 3.6 m depending on the system.
- Corner opening. Sliding panels meeting at a corner with no post, for extensions open on two sides.
Questions about sliding doors for extensions in Radlett
How soon can you survey in Radlett?
Surveys in the WD7 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.
What structural opening size should my builder leave for sliding doors?
Your builder should leave the structural opening size we give in writing for your chosen door, which is the frame size plus a small fitting tolerance on each side and at the head. The exact figure depends on the system and the threshold detail. We confirm it from your drawings early, then check the built opening before the door is made.
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.
How much do sliding doors for an extension cost?
Slimline sliding doors for an extension have a guide price of £7,795–£9,495 for a 3.6 m opening and £9,595–£11,695 for a 4.8 m opening, fitted, inc VAT at standard 2.1 m height. Taller doors, extra panels, special glass and flush thresholds move the price. Your written quote after the check survey fixes it.