A single-storey extension is a new ground-floor room built onto your house, usually at the rear or side, with its own foundations, walls and roof, creating a bigger kitchen, living space or bedroom without moving home.
Whatever prompted you to look into a single-storey extension, whether wear and tear, a growing family or plans to move, we can survey your Horsforth home and give you a price in writing. Homes in Yorkshire and the Humber typically come in at £33,000–£70,000, VAT included, for this kind of work. We also cover Yeadon, Pudsey and Guiseley, and the same steps apply wherever you are in West Yorkshire.
- Guide price
- £33,000–£70,000 inc VAT
- Time on site
- 10–16 weeks on site
- Postcodes
- LS5, LS13, LS16, LS18 and LS19
- Planning rules
- England
- Local area
- Leeds
- Survey
- Free, with a written quote
What should you budget for a single-storey extension in Horsforth?
No two jobs cost exactly the same, but the ranges below give a fair picture of a single-storey extension in Horsforth. Pricing for Yorkshire and the Humber runs about 6% below the national guide, and the overall guide is £33,000–£70,000 with VAT included. We'll confirm your figure after surveying the property for free.
| Type of job | What it usually involves | Guide in Horsforth |
|---|---|---|
| Small extension (8–12m²) | A modest rear or side extension, such as a utility room or a slightly larger kitchen. | £20,500–£37,500 |
| Typical rear extension (15–25m²) | A kitchen-diner or family room with bifold doors and a rooflight or lantern. | £33,000–£70,000 |
| Large or wrap-around (30m² plus) | A wrap-around or wide rear extension, often with structural steelwork into the house. | £66,000–£122,000 |
What moves the price up or down:
- Floor area, shape and number of corners
- Roof type, rooflights, lanterns and the amount of glazing
- Steelwork needed to open into the existing house
- Finishes, kitchen, flooring and heating specification
What’s included?
- Cavity walls built and insulated to building regulations
- Steel beams to open into the existing house
- Electrics and plumbing by qualified trades, with certificates
- Windows and external doors, including bifolds if chosen
- Plastering, screed floor and internal doors
- Building control inspections and completion certificate
Local housing and a single-storey extension
Leeds and Bradford are known for back-to-back and through terraces, many in sandstone or millstone grit, with stone-slate roofs on older properties. Halifax, Huddersfield and the Calder valley have mill-town stone terraces climbing steep hillsides, and interwar semis, post-war estates and newer housing surround the larger towns.
Back-to-backs and through terraces often suit dormer loft conversions and careful kitchen layouts. Stone properties commonly need repointing with suitable mortar, roof repairs and window replacement, and hillside plots can need retaining walls.
Knowing the typical building types in West Yorkshire helps, but a survey of your own home in Horsforth is what decides the right approach to a single-storey extension.
Planning and building rules in Horsforth
Horsforth is in England, so the planning and building rules set out below are the ones that apply. We confirm the details with the council before we quote.
In England, many single-storey rear extensions are permitted development: typically up to 3 m deep on a semi-detached or terraced house and 4 m on a detached house, no more than 4 m high, and covering no more than half the land around the original house. Larger rear extensions can go through the prior approval process. Side extensions, flats, listed buildings, conservation areas and homes where permitted development rights have been removed need planning permission.
Building Regulations approval is needed for almost every extension, covering foundations, structure, insulation, drainage, ventilation and fire safety. If the work is on or near a shared wall or boundary, the Party Wall etc. Act 1996 may apply.
Rules change and every property is different, so we check the planning history and constraints for your address before we quote.
How does the job run?
A visit to your home
A free survey comes first. It gives us what we need to price a single-storey extension properly, including dimensions, existing materials and access for deliveries, and gives you the chance to ask anything you like.
Your fixed price
The quote arrives in writing, not over the phone. It covers the full scope, the finishes you've chosen, any exclusions and the payment schedule, with a fixed price tied to that specification.
Dates and permissions
Once you accept, we agree start dates, order materials and deal with any planning, building control or neighbour notices the job needs. You'll know who is coming and when before work begins.
Build and hand over
During the work we protect the areas around it and tidy up at the end of each day. Once complete, we check the finish, remove our materials and hand over paperwork such as building control sign-off where it applies.
What you can expect from us
Questions about a single-storey extension in Horsforth
What is the Party Wall Act and does it apply to me?
The Party Wall etc. Act 1996 applies in England and Wales only. In England and Wales, it requires you to give notice to neighbours before certain work on or near a shared wall, such as digging foundations within 3m of their building and deeper than its footings. Neighbours can agree or appoint a surveyor. Scotland and Northern Ireland have no equivalent Act, though general rights still apply. We identify whether notices are needed during the survey.
Is a flat roof or a pitched roof better on an extension?
A flat roof is quicker to build and usually costs less, gives a clean modern look and works well with a roof lantern. A pitched roof matches the main house, sheds water faster and allows a vaulted ceiling, but it costs more and its height can affect neighbours. Modern flat roofs in EPDM rubber or GRP last well when properly detailed. Planning rules on height can also decide the choice.
How long does a single-storey extension take to build?
A single-storey extension usually takes 10–16 weeks on site, from digging foundations to final plastering. Bad weather, deep foundations or a complex roof can add time. Before work starts, allow several weeks for drawings, structural calculations and building control approval, and longer if planning permission is needed. We give you a stage-by-stage programme with your quote so you know what happens each week.
Do I need planning permission in Horsforth?
It depends on the work, the size of the project, your property type and whether the building is listed or in a conservation area. Horsforth is in England, so England's rules apply. Many smaller jobs need no planning application, but some still need building control approval. We check what applies to your address before quoting.
How much will a single-storey extension cost in Horsforth?
As a guide, expect to pay £33,000–£70,000 including VAT for a single-storey extension in Horsforth. That range is adjusted for Yorkshire and the Humber, which runs about 6% below the national guide. Where your project lands depends on size, materials, access and the condition of what is already there. We confirm a fixed price in writing after a free survey of your home.
Near Horsforth
We welcome enquiries from all LS5, LS13, LS16 and LS18 postcodes in Horsforth, plus Yeadon, Pudsey and Guiseley. Each one gets the same survey at no charge and a written price fixed for the work described.

