Downsize Existing House 2D Plans

The enclosed plans house size works out at around 317sqm and is expensive to build, I now require downsizing the house so that it is a much more cost effective size to build. The plans must be ready for planning permission and building warrant stage for Scotland UK I would like to work to stock size type materials to make the build cost effective. I would like as many windows as possible with bi-fold doors on the front ground floor for the sea view from the open plan living/kitchen/dining area, maybe the largest stock size that [login to view URL] 4790 wide x 2090mm high On the ground floor, totally open plan living/dining/kitchen area taking in the sea view, with separate downstairs toilet and utility room. On the first floor towards the sea, main bedroom with en-suite and the second bedroom next door which will be used as a study, both with Juliet balconies and french doors and any further windows that we would be allowed for the sea view. The two further bedrooms to the rear with main bathroom. The exterior has to be in keeping with the surrounding properties, such as white render, grey slate roof tiles and grey windows etc…