- Postcode district
- BH25
- 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
- Christchurch, Lymington, Ringwood
- Building rules
- England
Sliding doors for extensions and garden rooms in New Milton: what to know
Before you settle on a door type, it helps to know what sliding doors for extensions do well and what to check before you order.
When your New Milton extension is going through Building Control, keep the energy information for the doors to hand, as the inspector may ask for it.
For a garden room at the bottom of a New Milton garden, think about access: large glass panels need a clear route from the road to the site.
- Telling the engineer the door type and span early lets them design the beam above it to limit deflection, protecting the smooth running of large sliding panels.
- We provide the structural opening size and fitting tolerances in writing, giving your builder a clear target and avoiding disputes about who measured what.
- 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 New Milton
Sun angles matter for big glazed doors. Around New Milton, midday sun reaches about 63° in summer and drops to about 16° in winter. That low winter sun is free heat through south-facing glass; high summer sun is easier to shade with a roof overhang, and solar-control glass helps where there is none.
Guide prices for sliding doors for extensions in New Milton
These are guide prices for fitted doors, including VAT. They run from an entry-level system to a premium one at the same size; the survey confirms which suits your opening.
| Overall width | Typical panels | Guide price (fitted, inc VAT) |
|---|---|---|
| 1.8 m | 2 panels | £5,095–£6,195 |
| 2.1 m | 2 panels | £5,495–£6,795 |
| 6.0 m | 4 panels | £11,395–£13,895 |
See every size on the sliding doors for extensions page or try the guide price tool.
Survey, manufacture and fitting around New Milton
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 Christchurch or Lymington, the same process and prices apply.
Do you need approval in New Milton?
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.
Choosing the specification
- Triple glazing. For low-energy extensions or north-facing walls, subject to panel size limits.
- Solar-control glass. Coated glass for south- and west-facing extensions prone to summer overheating.
- Corner opening. Sliding panels meeting at a corner with no post, for extensions open on two sides.
Questions about sliding doors for extensions in New Milton
Can you match other doors and windows in my New Milton home?
Usually, yes. Most aluminium and uPVC systems come in standard RAL colours and finishes, and we can quote dual colour where the inside and outside need to differ. Bring photos of existing frames to the survey.
When should I order sliding doors for an extension?
Order sliding doors for an extension as soon as the opening is built and a check survey can be done, and agree the target fitting date with your builder in advance. Slimline doors typically take 6–8 weeks to make after sign-off. Getting a quote from drawings early means the specification is settled and only the final measurements are needed.
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.
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.

