Single-Storey Extensions

About our single-storey extensions service

A single-storey extension is the most common way a Nottingham home gains real usable space. It works on the ground floor only, which keeps the structural problem simpler than a two-storey build, keeps the roof of the existing house largely untouched, and in many cases avoids a full planning application altogether. For a 1930s semi in West Bridgford, a Victorian terrace in Sherwood or a post-war house in Arnold, it is usually the shortest route from a cramped galley kitchen to an open kitchen-dining-living space that the whole household actually uses.

We handle single-storey extensions end to end: measured survey, layout options, structural calculations, the permitted development or planning route, building control notification, and the build itself. That matters because most of the cost risk in an extension sits in the ground and in the structure — the foundation depth once a trial hole is dug, the beam size once the opening into the existing house is confirmed, the drain run that turns out to cross the footprint. Those decisions are engineering decisions, and we would rather resolve them on paper before you commit to a figure.

The first question is almost always whether you need planning permission. Many single-storey rear extensions fall inside permitted development if they stay within the depth, height and boundary limits set out in the General Permitted Development Order, and if the house has not already used up its allowance. Flats do not have permitted development rights at all. Houses in conservation areas, listed buildings, and homes where a previous owner removed the rights by condition are treated differently. We check the constraints for your specific address and tell you plainly which route applies rather than assuming the easiest one.

Building regulations apply either way. A single-storey extension needs adequate foundations for the ground conditions, a floor build-up that meets current insulation standards, a structural opening that is properly designed and supported, drainage that is either diverted or built over with agreement, and glazing that satisfies the thermal and safety requirements. Building control inspects at set stages. We notify, book and attend those inspections, and we hand over the completion certificate at the end because you will need it when you sell.

Layout is where a single-storey extension is won or lost. Adding four metres to the back of a house does nothing on its own — what changes the way the house feels is where the structural opening sits, how deep the room is before daylight runs out, and whether the new space still leaves you somewhere to put coats, bins and a utility. We usually look at two or three arrangements before settling, including options that reconfigure existing rooms rather than only adding to them. Rooflights, a partly glazed flat roof, or a pitched roof with a lantern are the usual answers to daylight at the back of a deep plan.

On site, the sequence is predictable and we share it in writing: set out and dig, foundations and drainage, substructure and slab, external walls up to plate level, roof, then the structural opening into the existing house, then windows and doors, first fix, plaster, second fix and finishes. The opening into the house is deliberately late in that order so your home stays weathertight and secure for as long as possible. Most single-storey extensions we build run between ten and eighteen weeks on site, depending on size, ground conditions and how much internal reconfiguration comes with them.

We are based in West Bridgford and most of our work sits inside a twenty-five mile radius of Nottingham, so we are dealing with the same local authorities, the same building control teams and the same housing stock week after week. That is not a marketing point — it is why we can tell you early that a particular boundary position or a shared drain is likely to be the constraint on your project rather than discovering it after the digger arrives.

What's included

• Measured survey and feasibility

  We survey the existing house, check the boundary positions and confirm what footprint is realistic before any drawings start.

• Layout and design options

  Two or three arrangements compared for daylight, circulation and cost, including reconfiguring existing rooms where that gives a better result.

• Planning or permitted development

  We establish which route your address qualifies for and prepare and submit the application or lawful development certificate.

• Structural calculations

  Foundation design for the ground conditions found on site, plus beam and lintel design for the opening into the existing house.

• Building control and drainage

  Full plans or building notice submission, inspection stages booked and attended, and any build-over or diversion agreement handled.

• Construction and finishes

  Groundworks through to plaster, decoration, flooring and the electrical and heating alterations the new layout needs.

Key benefits

• Simpler structure than two storeys

  Working at ground level only avoids interference with the existing roof and upstairs rooms, which shortens the programme and lowers risk.

• Often permitted development

  Many rear and side single-storey extensions fall within permitted development limits, removing the planning risk from your timeline.

• You keep living in the house

  Because the opening into the existing house is left until late in the build, most households stay in place throughout.

• Genuinely open-plan ground floor

  Combining a new footprint with a properly designed structural opening is what turns separate small rooms into one usable space.

• Better insulation than the original house

  New floors, walls, roof and glazing are built to current standards, so the extension is usually the warmest part of the house.

• One contract, one point of responsibility

  Design, engineering, approvals and build sit with the same team, so nobody can hand the problem sideways.

Project types we cover

• Single-storey rear extensions
• Side infill extensions
• Kitchen-diner extensions
• Family room extensions
• Utility and boot room extensions
• Ground-floor bedroom and wet room extensions
• Home office and garden room extensions

Our process

1. 1
   Site visit and brief

   We walk the house with you, measure the constraints and talk about what is not working in the current layout.

2. 2
   Options and budget range

   You get sketch options with an honest cost range, before drawings are developed in detail.

3. 3
   Approvals

   Planning application, prior approval or lawful development certificate as appropriate, plus building control submission.

4. 4
   Engineering and fixed price

   Structural calculations completed, then a written fixed-price quotation with a stage-by-stage programme.

5. 5
   Build

   Groundworks, structure, roof, opening into the house, then first fix, plaster and second fix, with weekly written updates.

6. 6
   Completion and certificate

   Snagging list closed out, building control completion certificate issued, and a twelve-month defects period.

Why choose Design N Build Construction Company

• Local to Nottingham

  Based in West Bridgford, working mainly within twenty-five miles, so we know the local housing stock and the local building control teams.

• Design and build in one place

  The people producing the drawings are the people who have to build them, which removes the usual gap between design and buildability.

• Engineering resolved before pricing

  Foundations and beams designed before you get a fixed price, so the figure is not padded with unknowns.

• Straight answers about planning

  If your address will not support what you want, we say so at the first visit rather than after a failed application.

• Written programme, weekly updates

  You know the sequence, the current stage and what is next, in writing, throughout the build.

• Certification handed over

  You finish with the building control completion certificate and the paperwork a future buyer's solicitor will ask for.

Frequently asked questions

Talk to us about your project

If you are weighing up a single-storey extension, the useful next step is a conversation about your actual house rather than a generic quotation. Call us or send a WhatsApp message and we will arrange a visit, look at the boundaries and drainage, talk through the planning route for your address, and follow up in writing with realistic options and a cost range.