Whilst you go through the process of designing and building your new dream home, you will be making literally hundreds of decisions. - Each and every one of them will have an impact on the cost of the finished project. - Some positive, some negative.

If you are working to a budget, the best time to start to think about the implications of your decisions is on “Day 1”.

In other words: From the moment you pick up a pen and a pad of paper, and start to sketch out some of your ideas and designs, you should be thinking about both the “practical” and the “cost” implications of every line you draw and every item you include in the design.

This section is going to cover some of the things, that, if you are on a tight budget, you need to bear in mind. - From when you first start to think about the layout and external appearance of your new home, through the whole of the design and Planning process, - and beyond.

As possibly a “first time builder”, you can’t be expected to be fully aware of how each line you draw on your design sketches will affect the cost of the project. but, if you bear in mind some “general guide lines”, you can use them to help to create a design which is going to give you what you want and need in the way of your designs, and also give you the best chance of keeping the overall build costs within your budget.

When I said that you need to think about the cost implications of every decision you make, from “the moment you pick up pen and paper”, - That was not quite correct! – You actually need to start earlier than that!

Before you even start to design your “dream home”, it’s well worth taking a bit of time to have a look around at other houses which have already been completed, to see:

·         What you like and what you don’t like,

·         What ideas you think you could use to help you keep within you own particular budget.

If you take the time to that bit of initial research, AND you then read all sections of this guide which deal with “design”, and the early parts of the project, then, when you do actually sit down, with your pen and paper, you will already be in a strong position to be able to incorporate what you have learned, into your initial designs.

If you just bear that one simple rule, you will be well on your way to designing a house which will be cheaper to build.

On one sheet, draw a square, measuring (scaled down) 10m x 10m (or, say 10cm x 10cm if you are using a ruler – this will be equal to a 1:100 scale ).

You will have drawn shape which encloses 100sq.m.

On the other sheet, now draw a shape measuring 5m x 15m. - You will drawn a shape that encloses 75sq.m

Both the shapes have identical perimeter lengths (40m). - But one encloses 25 sq m less internal area than the other. - In other words the second example encloses just 75% of the internal area of the first.

The 25% of extra space inside, for the same amount of external wall would basically come to you free if you design your house using the 10m x 10m shape for your design as opposed to the 5m x 15m shape.

If your total “build costs” turned out to be £50,000 , then the 10m x 10m design would have cost you around £46 / sq ft. The 15m x 5m design would have cost you £61 / sq ft, and it would have given you a smaller house in the process!

At one corner of your 10m x 10m shape, add another box on measuring 5m x 5m (this could represent  a utility room, w/c, or something similar ).

Now, on the other piece of paper, add another box to one corner of the 15m x 5m shape, measuring 7m x 3m ( denoting the same sort of room ).

The 10m x 10m shape, plus its additional box of 5m x 5m now has a perimeter of 50m, and encloses an area of 125 sq.m

The 15m x 5m shape, plus its additional box of 7m x 3m now has a perimeter of 54m, and encloses an area of 96 sq m.

The external perimeter of the second box has now increased to 4m more than the first, even though we have used 2 boxes with the same perimeters for each example!

Although it now has 4m extra “perimeter”, the second box now encloses 29 sq m less space than the first box.

What that shows us is that the shape of your building is important, and the more you head towards a generally “square” shape, the more space you enclose for the same price. – Which therefore brings you price per sq ft down, - which in turn may allow you to build a larger house for the same price.

The second part of this example shows is that “add ons”, to the basic shape make the overall design, even less efficient when it comes to the amount of space enclosed by the same amount of perimeter length.

The first example was just a plain box The second had a second box “stuck on the side” (possibly a “single storey extension for a utility room).

From a design perspective, it would be a better option, rather than adding the annex, just to increase the size of the main structure, and keep to 4 walls and the 4 corners.

If you have a plot which is part “flat” and part “sloping”. - If you are trying to keep build costs down, you would generally be advised to build on the flat area.

There are many reasons for this. – Too many to go into detail to in this section (they are discussed on other sections of this guide), but if you just remember the fact that building on sloping land can be very expensive, you will at least be aware of the fact, - enough to bear it in mind as you decide where to position the new property on your plot.

If your designer is telling you about this “wonderful new product” which he would like to try out, or add to the design for some reason, ask 2 questions:

1) Do I NEED it?

2) How much does it cost? – If you don’t need it and it’s expensive, don’t have it! - Try to stick to products that are well known and have been around for a long time. - They will generally be the cheapest. – If you keep this in mind throughout the project it could save you a substantial amount of money.

There are various types of ground floor construction you can use. They will all have their merits depending on each individual site. Talk to your designer about the various choices and the cost implications for your project, of each.

Think about a “powerfloated” concrete floor instead of “concrete and a screed”.

Screed is often just used to give a smooth surface for your finished floor. - Sometimes it’s needed to contain the “underfloor heating”,  and you can also se it to increase your insulation values, but often, you could manage without it.

If you screed a floor, not only will it cost you upwards of £1000, but there are also the practical implications of “when and who” can do it.

Once it is laid you have to keep off it for a few of days (which can stop work on that particular part of the job), and it then takes several months to fully dry out.

“Powerfloating” gives you the smooth finished surface within hours of you pouring the slab, which you can normally walk on within 48 hours.

If your Groundworker is capable of good quality power floating (ask for references, or see work already done), you may only be charged a few pounds extra over the cost of laying the basic concrete slab, to cover the cost of the guy who has to stay late on the day you pour the slab to power float it as it “goes off”.

A good powerfloated slab can be just as “acceptable” as a good quality screeded floor.

Facing bricks can vary in price hugely,-  from as little as £150 / thousand to many hundreds of pounds / thousand.

So, before you see one that you like, and simply say “that’s what we want”, - check on its price. It may be £200 / 1000 or it may be £400/ 1000.

If you need 20,000 bricks for your project and you pay £200 / 1000 more than you need to, you will be spending an extra £4,000! – On one item!

There may be something available, maybe at another merchant that is very similar to the one you like which could be half the price of the one you initially found and liked. Saving you thousands of pounds.

The same goes for blocks:

The cheapest blocks tend to be “solid concrete blocks” and the prices go up from there. - You have to balance the price of the block with the need to achieve “thermal insulation values” in the walls and in the structure as a whole.

Bear in mind the equation of “cost of block plus cost of insulation” when you choose the best combination for satisfying the thermal requirements in your external walls (talk to your merchant about this, - they will often be able to provide calculations for each combinations which will show the comparison between cost and insulation values).

Special Quoins are nice to look at, and can increase the value of your property, but can be expensive.

If your budget is tight, you can create a similar effect for less cost, by using a “contrasting coloured brick” which can be laid to simulate the appearance of the stone quoins.

You would usually need to specify what you plan to do and what bricks you intend to use, in your “Reserved Matters” Planning application.

Joists: Your designer will guide you here, but a standard 8” x 2” floor joist will span up to around 12’.

If you go above this span you may have to “upgrade” the joists to a larger size (maybe 9” x 2”). These joists may not be a “stcok item” and may cost more, - which can obviously increase your “unit costs”.

Trusses: Can span substantial distances unsupported, - but as the span increases, there is more chance that the roof structure may have to be upgraded to avoid “sagging” at the centre of the span.

If you are able to provide a “support wall” somewhere along the span of the truss (preferably near the centre of the span), this will have the effect of reducing the overall span, and will also then reduce the likelihood of an upgraded roof structure being required.

Standard roofing felt is the cheapest to buy.

Large concrete roof tiles generally cost less than slate or other options, and small roof tiles generally cost more than large roof tiles.

Small roof tiles also require more batten and more labour input to fit them.

UPVC fascias and gutters can work out cheaper in both the short and long term than timber. - In the short term they won’t need decorating, and in the long term they will neither need decorating nor replacing for many more years than the timber equivalent.

Plastic is cheaper than clay, and is usually perfectly suitable for a residential development.

This applies to the drains themselves AND to the “Manholes” and “Catchpits”. (Plastic will not be approved in certain circumstances. – Check with your Local Authority ).

You generally need to include with your Planning Application, details of your driveway and some landscaping detail.

For drives, grey gravel is pretty much the cheapest, golden style gravel is also cost effective.

Brick pavers can be bought for anything between £5 and £50 / sq m.  - So if you specify them, then shopping around is worthwhile. 

“Imprinted concrete” will cost somewhere in the same price region as a decent brick paver.

A “Macadam” driveway will generally be substantially cheaper than a “brick paved” or an “imprinted drive”

Separate garages cost significantly more than “internal garages”.

An external garage is basically a completely separate development on its own, and as such has much higher “unit costs” than if you can include it as part of the overall structure.

Enlarging the main structure of the house to encompass the garage and give the same “net” floor area, is usually a much cheaper option than building a separate structure.