We all want to get the best ‘bang for our buck’, and as building a house will probably be the biggest expenditure you will ever make, it is crucial you maximise what you get for your well-earned ‘buck’.
Choose a Simple Design
Regardless of construction system, the design of your house will have a big influence on your build costs. The simpler the design the more cost-effective it will be — there is a reason most of the major housebuilders construct pretty simple ‘boxes’.
Often these houses are designed to be rectangular or a number of linked rectangles forming the footprint of the house. They also feature simple roof configurations and external finishing materials that are mass produced, resulting in relatively low costs when compared to more bespoke or high-end materials.
Most self builders rightly aspire to build something a lot more appealing, both in terms of design and finish, which will generally result in increased costs. However, if these costs are carefully controlled, you can minimise the increase and build a home with lots of ‘kerb appeal’ that you can be proud to call home.
Brief Your Architect as Best You Can
To begin, give your architect or designer as detailed a brief as you can on the house you want them to design for you (assuming you are not selecting a ‘standard’ or ‘slightly altered standard’ design on offer from many of the timber frame companies), including:
- the floor area
- minimum room dimensions
- how many bedrooms/bathrooms/en suites
Include photos of houses you like the look of and design features and finishes you would like incorporated.
A list of ‘must-haves’ and another of ‘would like to have if the budget allows’ will assist the architect. It can be a good idea to sketch something to give to the architect as a starter for 10, either using one of the many free online sketching tools available or by sketching on graph paper.
This process gets you thinking about how you would like your home to work for you, for example, how the various rooms could link. Remember to maximise the benefits of light/solar gain by having the living areas facing as near south as possible. The sun is a free source of heating for your home — be sure to use it!
Design a Cost-Effective Structure
Design the house footprint to, ideally, a 600mm ‘grid’ or, if that is too restrictive, a 300mm ‘grid’, measured from the inside face of the timber frame external walls. Why, I hear you ask. Well the timber frame studs are at 600mm centres, so you minimise the amount of timber studs and reduce the percentage of ‘coldbridging’.
Trusses are fitted at 600mm centres so you also reduce the number of trusses required. Chipboard/plywood/OSB flooring boards are 600/1,200mm wide x 2,400mm long, so you also reduce the number of boards required and the labour costs of cutting to accommodate ‘off grid’ dimensions and wastage. Plasterboard is 1,200mm wide, so again you reduce the number of boards required, labour and wastage.
Think About Roof Design
A lot of expenditure can be saved on roof designs, the simple duo-pitch roof being the most cost-effective. The more valleys, hip ends, hidden gutters, different spans/eaves, heights/ridge heights and so on, the more expensive the roof will be.
On one-and-a-half storey houses, if dormers/rooflights are positioned to accord with the 600mm ‘grid’ and are lined up on the front and rear elevations as opposed to ‘staggered’, the savings in trusses and a simplified design can be considerable.
Consider Ceiling Heights
Vaulted ceilings can create fantastic open spaces but come at a price. Using scissor trusses as opposed to beams/purlins and loose rafters can be a cost-effective way of achieving a vaulted ceiling. Ask your timber frame supplier to advise you.
Instruct your architect or architectural designer to design to ceiling heights that will accommodate standard plasterboard dimensions — typically 2,400/2,700/3,000mm + 5mm.
Unnecessary extra costs will result if a ceiling height of, say 2,550mm, is designed, as you’ll be paying for 2,700mm sheets of plasterboard, paying labour costs to cut it down 150mm in length and filling up skips with off- cuts incurring landfill costs.
However, if it was designed to be 2,705mm you benefit from an increased ceiling height, no additional labour cost, no need for skips and no landfill costs.
Don’t Forget Doors & Windows
Some timber frame manufacturers can supply external doors and windows as part of their package, be they timber, PVCu, composite or aluminium. As windows and doors form a large percentage of the building fabric costs, you should look at this element of your build very carefully to ensure that money is not being wasted or spent on any unnecessary items.
While introducing as much natural daylight into the home as possible is very desirable, this comes at a cost. In simple terms, the larger the area of external doors and windows the higher the cost.
If you’re on a tight budget, you can minimise costs by keeping the opening sections to a minimum (but remember that openings need to comply with Building Regulations regarding ventilation and fire escape requirements). The more bars/panes the windows have, the more it will cost, so ask yourself if you really need multi-pane windows on all elevations or would you be happy just to have them on the front elevation, for example?
Bi-fold doors have been increasing in popularity as a way of bringing the garden into the home, but how many days of the year in the UK can they be fully opened up and used? A far more cost-effective way of achieving a similar result is to fit patio or French doors, perhaps in conjunction with fixed light panes.
Fully-glazed feature gables are, again, in vogue. They will add considerable costs, as a portal frame (usually formed in steel) will be required to provide structural stability.
Save on the Staircase
Another area where you could save money is the staircase — namely, avoiding a complicated design unless it is an integral part of introducing the ‘wow factor’ internally. The most cost-effective stair is a straight flight closed riser stair.
Introducing open risers, exposed timber treads/risers, turners, and quarter/half landings will all add costs, as will a spiral staircase. On one-and-a-half storey houses the stair should ideally be positioned to run parallel with, rather than perpendicular, to the roof trusses. This will reduce the amount of structural elements required to support the roof.
Be careful about your choice of materials, too. A stair where oak is used for all exposed timbers can easily cost four to five times as much as a softwood staircase.
Choosing a Supplier
Fully research which timber frame manufacturers have experience in supplying to the self build sector and what packages they offer. Some will only supply the structural shell, while others will supply a comprehensive package incorporating everything a joiner would fit (with the exception of kitchen units). This can save you a lot of time and expense in having to quantify, source, order and take delivery of the myriad different materials required.
- A good reference is the Structural Timber Association’s website; it lists manufacturers that supply to self builders
- Always obtain a minimum of three quotes and carefully compare what has been included and, just as importantly, what has been excluded from their respective quotes. This way, you are comparing ‘apples with apples’. Your architect or designer should be able to assist you with this.
One final crucial point: don’t compromise on the thermal efficiency and airtightness of the building envelope (floors, walls, roof, windows and external doors). You get one chance to cost-effectively maximise the benefits that a well-insulated, airtight home will provide over its lifetime. With energy costs spiralling, this will always be money well spent.