Thinking of extending your home?

Extending your home is increasingly becoming a highly popular choice with homeowners who are looking for more space, finding a change of circumstances or even just wanting to 'spruce up' a tired property.

Home extensions can take many forms and can be used for any purpose that the client wishes them to be used for, from a simple porch extension or conservatory to a complex multi-storey extension used for a garage, utility, kitchen, living & dining room.

Types of extension

There are many different types of home extension, and each one has different considerations which need to be thought about. (See considerations section for further information) Some, although not necessarily all different types are listed below;

Porches

Porches are typically small extensions to the front of a house, although they can be much larger and can be built to the side or to the rear. They are generally simple structures of only brick dwarf walls and columns, windows and a door. They can be plastered or left as bare brick and generally have a light and possibly an electric socket.

Most porches do not require planning permission due to their size, although some do, and it is best to check, see 'do I require planning permission' section. As long as the porch is separated from the house by an internal door and it is not heated then it will not require building regulations certification. If you have electrics in it however, you must either use a Part P registered electrician or have the job inspected by the building control department and pay their fee. See 'what is building control' section.

Typical costs can start at around £2,500*

Conservatories

Fairly simple structures usually of UPVC although they can be made of timber or aluminium. Some conservatories require planning permission and some do not. See 'do I require planning permission' section. The rules on building control apply as to porches (above) also see 'what is building control' section.

Typical costs can start at around £5,000*

Sun-Rooms

A sun room is essentially a conservatory with a solid roof on it. This however brings in some complicated elements as the roof carries a lot of weight which cannot be borne onto the lightweight glazing alone. In order to make the structure sound, load-bearing elements must be introduced into the walls and through the roof tied back to the existing building. Most clients wishing to have a sunroom are looking for a 'seamless wall of glass'. Whilst this is possible it can be difficult to achieve and it is advisable to employ both an architectural company and a building company experienced in this type of project.

Rules for sun rooms are very similar to that of conservatories for Planning Permission. Building control permission will almost certainly be required.

Typical costs can start at around £12,000*

Single storey extension

Single storey extensions are simply an extension built onto a part of the house whereby one side (or more) of the extension adjoins the property and there is only the ground floor plus any basement built to it.

Main considerations here must be the size of the extension and its impact upon neighbours, how the roof will work with the existing building & specifically whether the same type of roof covering of the existing property can be used on the extension. Positions of flues, drains, excavations etc must all be considerd. See 'considerations' section.

In some instances planning permission will not be required for single storey extensions. Building control permission will almost certainly be required.

Typical costs can start at around £8-10,000*

Two storey or multi - storey extension

A multi-storey extension can, like a single storey extension, also be built to any part of the existing building. However, with an extension of more than one storey, the subject of nuisance towards neighbours is much stronger. In some instances it may be possible to build what you want without requiring planning permission, but we would strongly advise that you get a letter from the Planning Department to cover this.

Typical costs can start at around £25,000*

Over -structure extension (typically over-garage)

An over-structure extension is, as it sounds, where you are extending over the top of an existing structure such as a garage, a kitchen, a living or dining room etc.

Unfortunately this is not as simple as many people think.

Many houses, for example, have only single-skin brickwork for garages. This is not sufficient to build up-over as the new brick and block work above is twin-leaf. The solution is either to dig down through the garage floor, install a new foundation and a new inner leaf, or to install blockwork 'piers' in the garage and fix a steel beam over the top of these.

Similarly, building over the top of a kitchen or dining room which has a twin leaf wall but was built in the 60's, it cannot be guaranteed what condition the foundations are in, so generally it is necessary to dig a trial hole to investigate.

In terms of planning permission and building control, the rules about whether or not you need planning permission are far more difficult to define in these instances and depend on distances to boundaries, between neighbours, aspect ratios etc, and you are well advised to seek specialist advice. Building control permission will almost certainly be required.

Typical costs can start at around £22,000*

Loft conversions, basement conversions, & garage conversions

These are all types of home extensions also, but they are covered elsewhere on the website so we will not cover them in this section.

*Figures are based on work carried out around North East England between 2007 & 2008 and are not representative for the whole of the country.

Do I need Planning Permission?

Planning permission is to do with the external appearance of the building. The planning authority will ensure that the plans for your home are in keeping with the area and do not interfere with the ingress of light to or the enjoyment of your neighbours land.

Planning approval typically takes 6-8 weeks from the local authoritie's receipt of the application. The householder is required to pay a fee for a planning application, typically for an extension in England this is £150inc vat. You will usually also need someone to draw up the plans for you and their fee will depend upon the project and the area in question.

Whether or not you need planning permission for a house extension is a tricky question.

Most recently the rules and guidance on house extensions have been changed December 08, October 2008, and previously to that, July 08.

Changes have been made with the aim of making extensions more easy to do without the need for planning permission, but the changes back in July meant that when Planning permission is needed it is more difficult to get, so in fact the changes have both positive and negative effects.

It is impossible to list here every example of when you do and do not need planning permission, so instead we have given some simple, easy to follow advice.

• Check the advice on; http://www.planningportal.gov.uk/
  
• Specifically on this site look at; http://www.planningportal.gov.uk/uploads/hhg/houseguide.html this will give you typical advice on average householder projects.
  
• Call your local council, (you can find the number from a link in the website at number 1), ask for the planning office, describe your project and follow their advice.
  
• Call an architect or planning advisor in your local area for advice. Beware of calling a builder first, they may just want you to sign up to them to build the project and may tell you just what you want to hear!
  
• If you think that you do NOT need planning permission, you would be best advised to ask the council to confirm this to you in writing before you make a start on site.
  
• If you are in ANY doubt, assume that you DO need permission. It is far safer to obtain the permission and build it knowing that you have the permission rather than build it first and face the possibility of having to put in a retrospective application which could be refused.

What is Building Control Permission?

Building Control ensures that building work and the construction of certain structures is carried out to a high standard in the interest of the health, safety and welfare of the occupiers, users, the public at large and also in the interests of the environment.

Building Regulations approval can be done by the local authority or by a private registered company. It takes the form of either a full building control application or a building notice. The cost to the authority is the same, the difference is that with a full application the householder submits full, detailed plans which are checked thoroughly for compliance with the legislation before build starts, and then you must build to these. With a notice you are free to start building without submitting plans but should anything 'go wrong' on site then the inspecting building control officer has the power to make you re-do the work.

The fees related to the building regulations application differ by size of build, area of the country, type of work and cost of work and you should check with your local building control section as to what the fee will be.

The building regulations are very complex and cannot possibly be covered here.

It is safe to say that in order to design and construct a building that will meet the modern-day regulations a typical homeowner will require the services of specialists. It is possible that this can be obtained from a builder but a homeowner would be well advised to take on the services of an Architect or Project Manager to oversee the build stages.

Do I need Plans?

This question isn't too difficult. If you need planning permission then you need plans.

If you do not need planning permission then you may not need plans, but you need to think about the other possible problems;

• How will you get accurate prices from builders without plans to show your requirements?
  
• If you do need building control permission and you build only with a notice then you put yourself at risk of the inspecting officer telling you that things need to be re-done on-site. You must have a lot of trust in your builders to use this option.
  
• If anything goes 'wrong' with your builders and you don't have a drawing then you have nothing to show what they were 'supposed' to build.

Extending Considerations

There are many factors to consider when you are planning an extension. Some of these have been considered above such as planning and building control permission.

One large factor that influences extensions to all but detached houses is the Party Wall act.

This is where a householder must notify their neighbour of any work that they intend to carry out on or adjacent to the party wall (any wall or wall which separates the two properties, including boundary walls). This must be considered when you are planning extensions above structures which abut to another neighbour's wall, or when you are planning an extension whose foundations would come close to your neighbours boundary.

If you are not sure about whether or not the Party Wall act will affect you then you should seek advice from a professional such as an Architect or the local Planning Office.

Other considerations that you may need to be aware of include the following;

• Drainage - where is the current drainage? will you be affecting this? how will you link into this and are you allowed to?
  
• Foundations, are you near to any trees? do you have access for a small machine to your plot or will it need to be hand dug?, What are the ground conditions like?
  
• Do you have anywhere for storage for materials?
  
• Can deliveries easily reach your house?
  
• Where will you put a skip?
  
• What will you do about access for men and keys?
  
• Use tradesmen registered for their trades - electricians should be Part P registered, all gas workers should be CORGI registered, window fitters should be registered with FENSA, as just a few.

Choosing a builder

Choosing a builder can be a potential mine-field and is the part of the project that you need to spend a bit of time on. If you get a poor builder you could end up in a real mess with anything from a poor quality job to a job half finished and court proceedings.

Sadly there is no one place you can go to get a list of all 'good' builders, but you can follow some sound tips;

• Go to your local authority planning department or building control department and ask if they have a list of 'trusted' or 'approved' local tradesmen.
  
• Look out for 'trust mark' companies. They should have been vetted for competency.
  
• You are best to stay with VAT registered contractors as they are more likely to be legitimate and trustworthy.
  
• Ask what guarantees they offer. If they can offer insurance-backed guarantee work even at a slightly higher cost then this may be worth it.
  
• Use your set of drawings and invite no less than three contractors around to tender.
  
• Make SURE that they all tender for exactly the same thing. If they offer to add extras or say that something is not necessary ask them to stick exactly to the drawings with the tender and add any extras etc as a separate item on the tender.
  
• Get quotes in writing.
  
• Beware of any company that has only a mobile number on stationary.
  
• Quotes should be on a printed letterhead, beware of any company that does not advertise in this way.
  
• Quotes should be broken down to show exactly what they include and what they do not include. A quote showing just a cost for building work is not worth the paper it is written on!
  
• When you choose a contractor, ask to go and see and talk to at least two of their previous clients for similar types of work.
  
• Make sure that they carry insurance for public liability and employers liability.
  
• If anything does not feel right, walk away and start looking again.

Will extending add value to my property?

Extending can often add value to a property. It adds extra floor space, and depending upon your use of the room can add an extra bedroom, extend the kitchen, dining room, living room, add a garage, utility etc.

The only advice that will always be sound when considering extending is the following;

• Think what you are doing the extension for. Is it for you to live in or for your investment. If you are doing it to live in then the investment potential comes secondary and your enjoyment of the space is primary. In this case, you should create which rooms you wish and fit out and decorate as you like. If your requirement is primarily to add value then you should consult a couple of local estate agents with your plans, ask whether they will add value or whether they may have better suggestions for the use of the new space.
  
• If you are extending for investment then you should aim for a finish to suit the market. I.e. If your property was a flat or a terrace in a 'poor' area of the city then you would aim for basic fixtures and fittings to be done on a budget, but pay attention to the small details that don't cost much but look expensive. If the property is a large detached for example in an affluent area then you should aim for a high quality fit out as anything else will not suit the property.
  
• If you aim for investment you should decorate the property very plainly. Try not to 'put your stamp on it'. Most first time investors are too keen and try too hard to do this but reduce their final sale price because they have made the property too much 'their own'. Remember that you are decorating to sell. Plain colours, basic contemporary fittings and no frills will suit the majority of tastes best.

Text and Images for this page courtesy of RC Project Management