Design, Calculations and Building Control
House Extensions in Farnborough
Most house extensions enquiries in Farnborough start with a room that does not work and end with a question about what is holding the house up. Open Plan Homes Limited answers that question properly, with the load path established, the members sized and the calculations issued to Rushmoor Borough Council rather than assumed on site.
The order matters. Property first, then the structural position, then a written scope and price. Working the other way round is how projects end up being redesigned halfway through.
Farnborough, Hampshire
Local Considerations for House Extensions in Farnborough
- Planning authority
- Rushmoor Borough Council
- County
- Hampshire
- Typical ground
- Bagshot and Bracklesham sands and gravels, free draining across most of the town
- Party wall exposure
- The station area terraces share party walls on both sides, which means notices to two adjoining owners rather than one on a mid terrace project.
If you are weighing up house extensions in Farnborough, the part of town matters more than most people expect. The older core around Queensmead, Cove and North Camp is largely Victorian terraces around the station and Farnborough Street, and larger Edwardian houses toward Farnborough Park, whereas extensive interwar and post war housing across Cove and Southwood, plus recent apartment development around the town centre and the business park make up much of the rest. Those two groups behave differently once a wall comes out.
Any application for a Farnborough property goes to Rushmoor Borough Council: it is the local planning authority, with Hampshire County Council above it for highways matters such as skip permits and any scaffold that reaches the pavement. On top of that, the areas around St Michael's Abbey and Farnborough Hill carry heritage designations, and Rushmoor holds a local list alongside the statutory one. We check that position at the start rather than treating it as a formality at the end.
Cove and Southwood plots usually have side access, which makes beam delivery straightforward; the older terraces near the station rarely do, and that is the single biggest driver of cost difference between two otherwise identical Farnborough jobs. The station area terraces share party walls on both sides, which means notices to two adjoining owners rather than one on a mid terrace project. And underfoot, Farnborough is commonly Bagshot and Bracklesham sands and gravels, free draining across most of the town, which is worth confirming by investigation on any project that touches foundations.
What is included
House Extensions in Farnborough: What Is Involved
Here is what house extensions covers on a Farnborough property. The scope is the same wherever you are; what varies is the structural picture we find when we get there.
Planning Advice and Drawings
Existing and proposed drawings prepared to the standard the local authority expects, with advice on whether permitted development is even in play.
Building Regulation Support
The technical detail behind the drawings, from insulation and ventilation to structural openings, prepared for building control.
Existing Opening Assessment
Where the extension joins the existing house, the load path through that junction is designed rather than assumed.
Single and Double Storey Extensions
Layouts worked up around how you actually want to use the space, not around a standard footprint.
The structural question
The Part That Decides the Job
On a Farnborough property this is the point where guesswork gets expensive, and it is why we establish the load path before anything is priced.
An extension usually creates the widest structural opening in the house, because the old rear wall becomes an internal opening. That wall is very often load bearing, carrying floor joists, the roof, or both. Sizing the beam means working out what is actually resting on it, allowing for the span, and then checking what the beam bears onto at each end, since a correctly sized beam sitting on inadequate padstones or an unreinforced pier simply moves the problem down the wall.

Questions we get asked
House Extensions in Farnborough: Frequently Asked Questions
Will a project in Farnborough need a party wall notice?
The station area terraces share party walls on both sides, which means notices to two adjoining owners rather than one on a mid terrace project. If the property is semi detached or terraced, or if the foundations for any new element sit close to a boundary, the Party Wall etc. Act 1996 is likely to apply and notice has to be served before work starts. We can confirm the position once we have seen the property, and serve the notices as part of the same project rather than leaving you to arrange it separately.
What does an extension actually cost to design and get approved?
Design, structural calculations and building regulations support are priced against the scope of the project rather than a fixed rate, and we set that out in writing before anything starts.
Do you also work in the areas around Farnborough?
Yes. Alongside Farnborough we regularly work in Aldershot, Farnham and Camberley, and across the wider Hampshire border area from our office in Fleet. Bear in mind that some of those neighbouring towns sit under a different council to Farnborough, so the planning and building control route can change from one to the next even over a short distance.
Do you cover the whole of Farnborough, including Queensmead?
Yes. Farnborough is fully within our normal working area for house extensions, from Queensmead, Cove, North Camp and Farnborough Airport through to the surrounding streets. Cove and Southwood plots usually have side access, which makes beam delivery straightforward; the older terraces near the station rarely do, and that is the single biggest driver of cost difference between two otherwise identical Farnborough jobs.
Can you work with drawings an architect has already produced?
Yes. If the design work is done, we can pick up the structural calculations and the building regulations detail from the existing drawings, provided the drawings reflect what is actually on site.
How long does an extension project take from first contact to approval?
The design and structural work is usually the quicker part. The variable is the approval route, since a full planning application runs to a statutory determination period while a permitted development scheme can move straight to building regulations.
Does the ground in Farnborough affect the foundation design?
It can. Across Farnborough the underlying ground is commonly Bagshot and Bracklesham sands and gravels, free draining across most of the town, and that has a bearing on foundation depth, on how a new bearing is detailed, and on how close to mature trees a foundation can sensibly go. That is a general description of the area rather than a statement about any particular plot, so where foundations are involved we design against what an investigation on the site actually shows.
Will removing the old rear wall need a steel beam?
Usually, if that wall carries load. The size depends on the span, what sits above it, and whether a flat or pitched roof loads it. In some cases a proprietary lintel is sufficient, but the calculation is what decides that, not the appearance of the wall.
Are there heritage or planning constraints to watch in Farnborough?
Yes. The areas around St Michael's Abbey and Farnborough Hill carry heritage designations, and Rushmoor holds a local list alongside the statutory one. Where any of that applies to a property, permitted development cannot be assumed, and on a listed building even internal alterations can need consent. We establish which of these apply to your address at the start, because it can change the structural solution as well as the paperwork.
Which council handles building control for house extensions in Farnborough?
Farnborough falls under Rushmoor Borough Council. It is the local planning authority, with Hampshire County Council above it for highways matters such as skip permits and any scaffold that reaches the pavement. That matters because a set of calculations and drawings has to be submitted to the authority that actually covers the address, and on this patch the boundaries run close together, so neighbouring towns can sit with entirely different councils.
Nearby and related
More Around Farnborough
House Extensions near Farnborough
Our other services in Farnborough
Talk it through first
House Extensions in Farnborough
Tell us what you are trying to do with the space and we will tell you what it involves. We are based at First Floor, 30 Reading Road South, Fleet, and Farnborough is well within our normal working area. Every project gets a written scope and price after we have seen the property.
