Costs Of Extending Your Property

It is impossible to give a simple guide to the cost of a house extension because there are so many factors that affect it. For a very basic round figure of building costs £1000/m² of floor area is sometimes quoted but this can vary significantly either way (particularly upwards) depending upon the exact nature of the project. We have listed some of the main factors that can affect home extension costs but obviously there may be others in some circumstances.

WHERE YOU LIVE
There are some regional differences in home extension costs, in particularly areas such as London where overheads and labour rates will tend to be higher it will be more costly. There could however be individual circumstances, such as being particularly inaccessible that might make some homes more costly to extend than others in the general locality.

SIZE AND SHAPE
In general terms very small house extensions will tend to be proportionately more expensive than larger ones, however beyond certain sizes (depending upon the construction) it may be necessary to have additional beams or columns and thicker walls etc. which would tend to reduce some of the savings due to its size. In general a simple floor plan of square or rectangular shape will be more economical to build than some highly complex scheme of interlocking octagons with an equally complicated roof!

THE NUMBER OF STOREYS OF THE HOME EXTENSION
A building of several storeys will often be cheaper to build than an equivalent area of single storey; this is in part due to there often being little difference in the foundations and roof by the addition of another storey. It should be borne in mind though that the Building Regulations have additional requirements particularly in relation to fire regulations, the higher the extension goes. At second floor level it will normally require a protected stairway (fire doors and walls around the stair area leading to a final exit door) and above this a separate means of escape. This could affect the existing building as well as the house extension. Where building over someone else’s property, which may occur with some extensions to flats, it should be borne in mind the floor will need to be built to a high sound proofing standard with implications in terms of cost.

WORK TO THE EXISTING HOUSE
Few home extensions involve just the building of the new part, it will often require some interconnection with the original house but there may be additional works as well, perhaps rearranging the layout in the existing part such as creating corridors, en-suites etc. It may be that with the additional accommodation the heating, plumbing and electrical systems will be stretched or in need of renewal anyway. Where there is a significant alteration to the roof it may be time to consider whether the existing tiles still have a reasonable lifespan, as such these additional expenses need to be added to the home extension costs.

QUALITY OF MATERIALS AND FINISH IN THE HOME EXTENSION
There can be considerable differences between the cost of materials between for example a very basic brick and tile and high quality hand made bricks and tiles. These differences can sometimes be even more marked with the internal finishes. A home extension containing a kitchen or bathroom will inevitably be more expensive than a fairly clear space such as a living room, but in addition to which there can be a vast difference between budget lines from DIY retailers and high end luxury products.

EXTENSIONS PARTLY WITHIN THE EXISTING STRUCTURE
On a price per square metre loft conversion costs and garage conversion costs will tend to be less than for new buildings provided the work required to upgrade them is not too extensive.

With basement costs, converting an essentially useable existing basement may be fairly economical whilst creating a totally new basement will tend to more expensive than other types of extension.

EXTENT OF THE WORK DONE BY YOURSELF
From an extreme case of a full DIY project, some people chose to do a part of the work. In most cases this will be just the final decoration but where one has particular skills such as plumbing, electrics, plastering then the builders costs will be less if these are not included in his quote. Be realistic though of your abilities and make sure you do not hold up the work the builder is contracted to do.

Some people manage the project using individual tradesmen and buying the materials themselves, this obviously saves the overheads and profit of a main contractor but can involve considerable time in sourcing labour and materials if you are not used to it and any mistakes maybe down to you.

DON’T FORGET THE VAT!
Most home extensions will be subject to VAT at the normal rate, new houses are zero rated whilst some types of conversions to residential use from other uses and houses that have been empty for two years or more are charged at a lower rate. Some works to listed buildings do not attract VAT, although this concession will be removed 1st October 2012, but these are complex areas that need to be researched for the individual circumstances. See HMRC website .Occasionally builders will not be registered for VAT, this will not be very often as it would not take many simple extensions in the course of a year to reach the threshold. Where it occurs the saving will not generally be the full amount of VAT as they will probably have had to pay VAT on the materials and probably to some sub-contractors.

OTHERS COSTS
In addition to the actual home extension costs there are a number of other charges etc. that will form part of most home extension projects. We have listed many of the typical ones although the list is not necessarily exhaustive, on the other hand for many fairly straightforward schemes a lot of the potential costs listed will not apply.

• Design Costs: Architectural and sometimes structural, interior, heating etc
• Council fees including town planning and building regulations and Community Infrastructure Levy (for extensions over 100m2.
• Party wall surveyor and associated costs,
• Covenant approvals etc.
• Costs associated with specific aspects of a scheme such as sewer build over agreement, arboricultural reports etc.
• Supervision or project management costs.
• Quantity surveyor.
• Other costs you may incur as a result of the work taking place, perhaps renting another property, renewal of carpets, curtains etc.

REDUCING HOME EXTENSION COSTS
There can be opportunities at several stages of the process to reduce costs. Here are some possible ideas:

Basic design stage
Do you actually need to extend or are there ways of rearranging the existing accommodation? If not entirely doing away with the need to extend it might reduce its size. See Internal alterations

Are there underutilised parts of the building such as integral garages, lofts etc. which may be more cost effective to convert?

Are there suitable parts of the building that may be built over such as previous ground floor extensions which might save on foundation costs etc? It does not necessarily need to be exactly the same size as the proposed extension, particularly with lighter weight forms of construction it is often possible to cantilever beyond the building below or set the building in and retain some roof around the lower building.

Does extending to other parts of the building save possible problems and expense of perhaps moving drains or other services?

If you live in a semi detached or terrace house is there potential to build at the same time as a neighbour? Party walls are generally cheaper and take up less room than two separate external walls and a larger project might obtain more competitive quotes.

Specification stage
A flat roof is often cheaper than a pitched roof; the materials used have improved so a longer life can be anticipated from it than was typical a few decades ago. It can also give a more contemporary appearance and can be particularly advantageous over irregular shaped buildings.

Consider contrasting wall materials particularly where the existing might be expensive materials such as handmade bricks or stone. Although it needs to be done with care to avoid it looking cheap, contrasting materials such as render to timber boarding can work well with other materials. Be aware though that you may not be within the definition of similar appearance under permitted development.

Bi-fold doors have become popular but are often more expensive than more conventional hinged or sliding doors which in turn can be more than windows. A combination of conventional hinged or sliding doors and windows may be more cost effective and give similar amount of light, whilst they may not open up as much how often is British weather suitable for that? With upper floors a full depth window may give a similar effect to doors and a Juliet balcony but at a lower cost.

With kitchens it is sometimes possible to combine carcases etc. from cheaper outlets with higher quality work tops etc. or even reuse existing carcases with new doors. Place orders for kitchens etc. during sale times provided they are prepared to hold onto them until actually required.There are also companies around dealing in second hand or ex-display designer kitchens which can enable you to purchase a quality kitchen at a fraction of the new cost.

With extensions such as raising the whole roof, this can sometimes be done in a way such that the existing structure is left in place until the new roof is weatherproof avoiding the need for expensive temporary roofs.

Building stage
Find out when builders in your area are generally less busy and try work around this for a more favourable price.

If you live in one of the more expensive parts of the country for building works see if recommended builders from outside the area would be prepared to travel in or if you can provide accommodation are willing to stay overnight.

It can be more of a gamble dealing with more recently established companies but they may be willing to negotiate a better price and may not be registered for VAT yet.

If you are prepared to spend time searching on the internet you may be able to get better prices for some items than tradesmen using their regular suppliers. This probably works best where you are employing them on a labour only basis although you may be able to come to some arrangement with them in other circumstances.

Where the work is fairly extensive consider moving out altogether if this can be done without significant costs as this enables the builder to program the works in a faster and more efficient way.

For very extensive works it may be worth considering demolishing the existing building and starting again. As well as potentially saving the VAT (see HMRC website) on new builds it may avoid any compromises in using the existing structure and would mean the building fully complies with new standards of insulation etc. However much your home extension may cost First Choice Finance could help you finance it, offering a selection of home owner loans that can be used for home improvements alternatively we could help you remortgage your property, releasing the equity you need to pay for your home extension.

Homeowner Secured Loans 9.8% APRC. Representative example: Borrow £50,000 over 180 months. 60 months at 8.1%, £497.83 pcm fixed at 60% LTV. Then 120 months at 10.1%, £539.89 pcm variable. Total payable £94,656.60. Total cost of credit £44,656.60 (including: £795 lender fee, £985 broker fee & £42,876.60 interest). First Choice are tied to certain loan providers.

Mortgages & Remortgages 8.4% APRC. Representative Example: Borrow £120,000 over 25 years at 5.99%, £778.86 pcm fixed for 3 years at 60% LTV. Then at 8.75%, £974.86 pcm, variable for 22 years. Total payable £286,416. Total cost of credit £166,416 (including: £985 broker fee, £999 lender fee & £164,432 interest)

Unsecured Personal Loans REPRESENTATIVE 49.9% APR (VARIABLE) First Choice are tied to certain unsecured lenders.

THINK CAREFULLY BEFORE SECURING OTHER DEBTS AGAINST YOUR HOME. YOUR HOME MAY BE REPOSSESSED IF YOU DO NOT KEEP UP REPAYMENTS ON A MORTGAGE OR ANY OTHER DEBT SECURED ON IT. Security is required on immovable property.

Late repayment can cause you serious money problems. For help, go to moneyhelper.org.uk

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