whats is the househould size versus loft/studi flat?

Please download the document using the following link. This document is a good guidance for space planning and it has all the minimum requirements you are after: https://www.gov.uk/government/publications/technical-housing-standards-nationally-described-space-standard

In all honesty, it depends! The technical standards referred to by Foreplans are used as a standard for all social housing in the UK which is funded by Government money. Most housing associations and newer council homes will be designed to that level to give a good design/value option. There are also almost always designed to have a level of flexibility built too, meaning that they could be adapted to meet the needs of varying access requirements (wheelchair users, use of crutches, the addition of a lift possibly etc) Private housebuilders and developers do tend to prefer to use their own standard house designs which generally have a smaller footprint than the technical standard. Sizes and designs are monitored in line with legislation (building regulations and manufacturer's recommendations) but are more mindful in their profit/value vs space/value comparisons.

Minimum room floor area where a kitchen is provided within the room If occupied by one person, not less than 11m2 If occupied by two persons, not less than 14m2 Minimum room floor area where a kitchen is provided in a separate room (either in adjacent room or annexe) If occupied by one person, not less than 9.5m2 If occupied by two persons, not less than 12m2 Kitchen facilities located in a separate room should have a minimum floor area of 4m2.

It depends on the client, budget, location and the property if it is an existing building or a new built.