Three deadlines in one autumn, and each one turns on a different date

A scheme can be caught by one and escape the other two. Getting this wrong is not a compliance problem, it is a land value problem, because each of the three has a price.

Between 30 September this year and 24 March next, three separate changes take effect, each with its own transitional test. They are being discussed separately, which is how schemes end up assuming that beating one deadline means beating all three. It does not.

Date	What changes	What fixes your position
30 September 2026	Second staircase required in new blocks of flats over 18 metres	Full plans application before date, and foundations started within 18 months of it.
1 October 2026	Building Safety Levy on residential schemes of 10 or more dwellings	The date of the Building Control application. Nothing else.
24 March 2027	Future Homes Standard. Heat pumps and solar on most new homes.	Application before the date and work started before 24 March 2028. Both.

The traps are in the differences

Take a scheme that gets a Building Control application in on 29 September. It escapes the levy, because the levy looks only at that date. Whether it escapes the second staircase requirement depends on whether it was a full plans application and whether foundations start within 18 months. Whether it escapes the Future Homes Standard depends on a different date again, since that one allows until 24 March 2027 to apply and 24 March 2028 to start.

What this is worth

Each of the three has a number attached. The levy is calculable today from published rates and chargeable floorspace. The Future Homes uplift is a per plot figure on heating, solar, fabric and incoming supply. The second staircase is an area loss rather than a cost, which makes it the largest of the three on a tall building and easiest to miss, because it does not appear in the build cost at all.

The practical version

Three questions, in this order. What is the Building Control application date, and is it realistic? Is the building over 18 metres? When will foundations actually start? Between them those three answers settle all of it, and none of them requires a cost consultant to answer. What does need a cost consultant is what the answers are worth, which is the point at which we can help.

What this means for your scheme

• Test each of the three separately. Beating one is not beating all three.

• The dates that matter are application dates and foundation dates, not planning and not completion.

• Model the outcomes rather than assuming one. A scheme close to any of these lines should be appraised in both ways.

• The staircase requirement is the one that will not show up in a build cost. It shows up in area.

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Sources. The Building Regulations etc. (Amendment) (England) Regulations 2026. The Building Safety Levy regulations and MHCLG guidance. The second staircase amendment and accompanying guidance. All linked, none reproduced.