The most fun can be had designing your possible new home and it is easy to rush to thinking about decor and interior design - whilst this is the most fun, it is the least important in the greater scheme of things.
Working alone or with your partner, family, architect, architectural designer, you need to be focussed on the skeleton of the house you want to live in - if the overalll design isn't the way you live, there is not a pretty wallpaper on the market that can put it right.
Some things to consider:
Your Design
Always remember this is the home you are going to live in - no disrespect to the professionals, but the architect will not be sitting next to you on the sofa. If you really like the design work of a particular architect, choose that architect and pretty much leave it to him/her. The reason you are paying him/her is because you want to achieve what they design.
If you know what you want, choose an architect that will do what you want and offer ideas that make sense.
Start With The Floor Plan
We advise thinking about the inside of your home before choosing cladding and window frame colours. It is inside that you will live. Imagine walking through the front door - what do you see? Sketch this as a floor plan. Don't use a ruler, whatever size you draw your entrance will lead you to the proportionate size of all other rooms as your own spacial awareness takes over. Go through the doors off the entrance and draw what you see. Add the occasional window/door and feature. Once everything is sketched - come in through the back door and make sure it all works. You can then draw the elevations based on the rooms, windows and doors you have sketched - and from that you can start tweaking and imagining what you would like to see as you come up the drive each day.
Budget
Don't start from "how much money have I got". Whatever your budget, your personality and deep knowledge of yourself knows what your limits are without having it in black and white in front of you. This stagnates imagination.
Start with what you really want - all the whistles and bells. Once you know how much that costs, you can take off the unnecessary extras first and you could still end up with the home you dream of - possibly on a smaller scale; probably without the Quooker tap and aluminium windows, ensuites for every bedroom and ceilings high enough for enormous chandeliers; but ostensibly, precisely the home you want perhaps with the skeleton to be able to add other bits and pieces when some money is back in the bank.
Square Metres Cost Money
Every square metre of floor space costs around £2000 for a new build - although some people have budgets significantly higher than this. And this should be considered as not including the kitchen - the cost of this can be as much or as little as you want it to be. This is the starting price is for a good quality home - without handmade staircases; 3m high ceilings throughout; Versailles flooring or silk wallpaper.
If you don't have a money tree planted in the garden, once you know how you want to live, you should just be aware of your budget. Once you have "the dream" on paper - think clever with space
Then Budget Again ....
The main reasons that builds go over budget are:
Borrowed Light Means Darker Areas
The rooms you live in are relatively easy to place in your new home - moving between them is the difficult bit. Hallways are needed and these almost always need to be in the middle of the house where there is little or no natural light. Try not to borrow light from other rooms - get some natural light in there! When it comes to building, there are always sun tunnels, "sunlight" bulbs and sensors to help with things if dark hallways cannot be avoided. Sun tunnels are jolly good - but plan for them at the very beginning as they need the right amount of space (false walls needed) to get from the roof to the hall ceiling.
Voids aren't free.
A floor to roof space provides a wonderful airy entrance hall but just because there are no rooms to the first floor doesn't mean this area is cost free. Invariably this design involves large feature windows (which means steel) and balustraded walkways - much more expensive than standard windows and hallways.
Eco Stuff
Most of the planet saving gadgetry requires lots of space - and needs to be planned for long, long before you start building. Some MVHR has 150mm diameter pipework that has to get to every room in the house; underfloor heating has manifold sets which need to be accessible; hot water cylinders are vast these days; a pellet burner will probably need its own house; the ubiquitous air source heat pump and its paraphernalia ....
Electronic Stuff
Along with the eco, the electronic gadgetry takes up lots and lots of space where it cannot be seen. Cat 6, wifi boosters, centralised sound system - these all need a cabinet in a cupboard - and plenty of space in the walls away from the general electrics. So another airing cupboard has gone.......
Times change
Most self-builders build a home they will be staying in for quite some considerable time, during which family members may change. Perhaps a couple of children will happen along; or move in to look after you when needed. Designing your home with attic trusses to allow you to go up a floor to make more bedrooms; or making sure the floor design is already in place for a lift; or thinking about how an annexe or garage could be added to the side of the house and be easily accessed from the original rooms by including that door at the outset -all useful and inexpensive things to prepare for when you first build.