Rear Extensions • Grantham, Lincolnshire
Rear extensions in Grantham — from survey to completion
We carry out rear extensions in Grantham and the surrounding Lincolnshire area from our base in West Bridgford, around 24 miles from Nottingham and inside our twenty-five mile working area. Extending the back of the house into the garden — single or double storey — most often to create a kitchen-diner or family room that connects to the outside. We handle design, structural engineering, approvals and construction as one contract, so the decisions that carry cost risk are made before you commit to a price rather than discovered once work has started.
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Rear Extensions in Grantham: how we approach the work
Our rear extension service in Grantham starts with a measured survey of your house rather than a generic quotation. Extending the back of the house into the garden — single or double storey — most often to create a kitchen-diner or family room that connects to the outside.
The technical crux on most Grantham projects is foundations, the beam over the opening into the house, daylight to the middle of the plan and drainage under the footprint. We resolve these on paper first — with a structural engineer where the work needs one — and price the job on what is actually there.
Planning in Grantham: Single-storey rear extensions are commonly permitted development within depth and height limits; larger depths use the neighbour consultation scheme, and two-storey schemes usually need an application. We check the constraints for your specific address, including any planning history, and tell you plainly which route applies before drawings are commissioned.
Why Grantham homeowners use a local design and build team
We are a local design and build contractor, not a national lead-generation site. Grantham is around 24 miles from Nottingham and inside our twenty-five mile working area, which means the same team that surveys your house is the one that designs it, prices it and builds it.
Cost is driven by depth and width, single or double storey, glazing to the garden, roof type and rooflights and internal re-planning. We do not publish a rate per square metre because it misleads more often than it helps; you receive an itemised, written fixed-price quotation after the survey so you can see what each element costs and what changes it.
We do not invent projects, reviews or statistics to fill a page. What we can promise is a written programme, weekly updates, building control certification handed over at the end, and a twelve-month defects period during which we return to put right anything that fails.
Planning permission in Grantham: South Kesteven District Council
The local planning authority for Grantham is South Kesteven District Council. Any application for your rear extension — householder planning permission, a lawful development certificate or prior approval — is submitted to South Kesteven and decided against its adopted local plan and national policy. Applications are made through the council's own planning pages or the national Planning Portal, where the current householder fee is published.
Single-storey rear extensions are commonly permitted development within depth and height limits; larger depths use the neighbour consultation scheme, and two-storey schemes usually need an application.
Householder planning application: The standard route for extensions and alterations that fall outside permitted development. Submitted with location and block plans, existing and proposed elevations and floor plans, and a fee set nationally; the council consults neighbours and publishes the decision on its planning register.
Party walls sit outside the council process entirely. Not a council process at all: the Party Wall etc. Act 1996 is a private notice served on the neighbour when work affects a shared wall, cuts into it, or excavates near their foundations. It runs alongside planning and building control, and being told about it late is what usually delays a start on site.
Before anything is drawn we check your address for the things that change the route: whether permitted development rights have been removed by a condition or an Article 4 direction, whether the property is listed or in a conservation area, any earlier planning decisions on the site, and the position of boundaries and highways.
In practice the order is: constraints check → measured survey → design that fits the route we have identified → submission to South Kesteven where an application is needed. Where the work is permitted development we recommend applying for a lawful development certificate, because it is the document that proves the position to a future buyer's solicitor.
Building regulations and building control in Grantham
Planning and building control are separate approvals. Even where your rear extension in Grantham needs no planning application, the building regulations still apply, and the work has to be notified. For Grantham that means East Midlands Building Consultancy, the shared building control service run with Rushcliffe and Newark and Sherwood, or a registered building control approver of your choice. We make the submission and manage it for you.
Building notice: A shorter route for straightforward work: the job is notified and then inspected as it proceeds, with no prior plan check. Faster to start, but the risk of a change being required mid-build sits with the owner.
Foundations, the beam over the opening into the house, daylight to the middle of the plan and drainage under the footprint. Those are the elements building control looks at, alongside insulation and airtightness, fire safety and escape, ventilation, drainage, glazing, and the safety of electrical and any gas work.
Inspections happen at set stages rather than all at the end — typically excavation and foundations before concrete, drainage before it is covered, the structural frame or beams once installed, insulation and damp proofing before they are hidden, and a final inspection on completion. We book these and meet the inspector on site so nothing is buried before it is signed off.
At the end you are handed the building control completion certificate, structural calculations, electrical certification, gas paperwork where relevant, and any planning or lawful development documents. Keep them together: this is the pack a buyer's solicitor asks for when you sell.
Council contacts for Grantham
South Kesteven District Council is the planning authority. Building control is handled by East Midlands Building Consultancy, the shared building control service run with Rushcliffe and Newark and Sherwood.
- Planning
- Building control
Details as published by the council. Fees and processing times change, so check the council's own page for the current figures — or let us handle the submission for you.
The process, step by step
1. Site visit in Grantham: we measure, look at the constraints — boundaries, drainage, structure, roof — and talk about what is not working in the house now.
2. Options and cost range: sketch options with an honest range, before detailed drawings.
3. Approvals: permitted development check, lawful development certificate or planning application as your address requires, plus building control submission.
4. Engineering and fixed price: structural calculations completed, then a written fixed-price quotation with a stage programme.
5. Build: roughly ten to eighteen weeks on site for single storey. Yes; the opening into the existing rooms is the last structural task.
6. Completion: snagging closed out, building control completion certificate issued, defects period begins.
Types of rear extensions we take on in Grantham
In Grantham and the surrounding area we take on kitchen-diner rear extensions, family room extensions, glazed garden rooms, double-storey rear extensions, extensions with utility rooms and extensions replacing conservatories. Housing stock varies street by street across Lincolnshire, so each project is designed for the actual house rather than adapted from a standard drawing.
Read the full Rear Extensions guide for design options, planning rules and what drives cost.
Areas we cover near Grantham
From Grantham we also cover Bottesford, Newark-on-Trent and Melton Mowbray, and the wider Lincolnshire area within roughly twenty-five miles of Nottingham. If you are just outside Grantham, tell us the postcode and we will confirm.
Talk to us about your Grantham project
The useful next step is a conversation about your actual house. Call us or send a WhatsApp message and we will arrange a visit to Grantham, look at the constraints properly, talk through the planning route for your address and follow up in writing with options and a realistic cost range.
Rear Extensions in Grantham: questions homeowners ask
Which council decides a planning application in Grantham?
South Kesteven District Council is the local planning authority for Grantham. We prepare the drawings and supporting information to the standard South Kesteven expects and submit the application on your behalf.
How long does a rear extension take in Grantham?
On site, roughly ten to eighteen weeks on site for single storey. Design, engineering and approvals before that usually add several weeks to a few months depending on the route, which is why we start the approvals process early.
How much does a rear extension cost in Grantham?
It depends on depth and width, single or double storey, glazing to the garden and the finish level. We do not quote from a rate per square metre; after a survey of your Grantham property you receive an itemised fixed-price quotation.
Can I stay in the house during a rear extension?
Yes; the opening into the existing rooms is the last structural task.
Do you handle building control for work in Grantham?
Yes. We notify building control — South Kesteven or an approved inspector — provide structural calculations where required, meet the inspector at each stage and hand you the completion certificate at the end.
Which areas near Grantham do you cover?
Bottesford, Newark-on-Trent and Melton Mowbray and the rest of Lincolnshire within roughly twenty-five miles of Nottingham. We are based in West Bridgford.
How much garden will I lose?
That is a design decision as much as a planning one. We show the footprint on a plan of your actual garden so you can judge the trade-off before drawings are developed.
Can a rear extension replace a conservatory?
Yes, and it is common. The new extension is built to full insulation standards, so the room is usable all year.
How do trees and ground conditions affect the foundations?
Clay soils and nearby trees usually mean deeper foundations, and the depth is set by the ground conditions and root influence at your address rather than by a standard detail. Foundations, the beam over the opening into the house, daylight to the middle of the plan and drainage under the footprint. We establish this before the fixed price so the foundation depth is not an open-ended extra.
What insulation and energy standards will apply?
Current building regulations set the standards for insulation, airtightness, glazing, ventilation and heating for the work, and they are checked by building control rather than left to the builder. The specification we quote for a rear extension in Grantham is written to meet them, and the detail is in your quotation rather than assumed.
Who prepares the drawings and structural calculations?
We do, as part of the same contract — measured survey, design drawings, planning submission where needed, and structural calculations from a chartered engineer where the work is structural. You are not left coordinating an architect, an engineer and a builder who have never spoken to each other.
How is access and parking handled on a Grantham street?
We agree access, skip position, material storage and working hours with you before we start, and let immediate neighbours know. Where the street is narrow or parking is restricted we plan deliveries around it, and any permits required for a skip or scaffold on the highway are arranged in advance.
How do payments work?
Against a written stage programme tied to completed work — never a large sum up front for work that has not happened. Each stage is set out in the quotation before you sign, so you know what has to be finished before the next payment falls due.
What happens if the survey uncovers something unexpected?
We tell you straight away, in writing, with the options and what each one costs before anything is done. Most surprises in older Lincolnshire housing stock — old wiring, unsupported walls, previous unapproved alterations, damp — are found because we look for them at survey stage rather than after the walls are open.
Do I need planning permission for a rear extension in Grantham?
Single-storey rear extensions are commonly permitted development within depth and height limits; larger depths use the neighbour consultation scheme, and two-storey schemes usually need an application. We check the planning history and constraints for your specific Grantham address before advising, and prepare the application or lawful development certificate where one is needed.
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Planning rear extensions in Grantham?
Call or WhatsApp for a site visit. Written options and an honest cost range, no pressure.