buildwiz.uk
Access Pass

Phase 5 · Specification · Task 01 of 01

Planning the Loft Layout: Head Height Zones, Eaves Storage and the Ensuite

Plan a loft conversion layout: head height zones, bed and stair position, eaves storage, and the ensuite decisions on soil stack, macerator, pressure and fans.

11 min readUpdated 2026Premium
Illustration in progress

A loft layout gets decided by two things you never see in a brochure: how much height is left under the slope, and where the soil stack runs down the house.

The loft company draws a layout. You decide it, before design sign-off, because the stair, the dormer, the drainage route and the windows all follow from where the bed and the ensuite go. Move the ensuite once the structure is designed and you pay for a redraw, and sometimes for a pump nobody planned on.

The rules below are for England. Wales has its own Approved Documents and Scotland uses Technical Handbooks.

Do this first

Two decisions come first: the stair position, from loft conversion stairs, and the hot water system, from clearing and preparing the loft, which decides whether a loft shower will work.

What this guide covers

  1. 01Read the section drawing, not the floor plan
  2. 02The bed, the stair and the windows
  3. 03Eaves storage and the cold behind it
  4. 04The ensuite starts at the soil stack
  5. 05When gravity won't reach: the pumped WC
  6. 06Water pressure: the loft shower is the highest outlet in the house
  7. 07Ventilation: the fan, the duct and the window
  8. 08Electrics in the ensuite
  9. 09Sound: the walls round the bedroom and the WC
  10. 10Who decides what
  11. 11Your design sign-off checklist

Premium content — unlock with an Access Pass

This guide is part of the buildwiz.uk Access Pass. Get full access to every project guide, planning through to completion.

Get Access Pass

£49, paid once. 24 months access.

Already bought the Access Pass? Sign in

General guidance for homeowners in England (and Wales where we say so), not professional advice. Every site is different: check anything that affects your build with a qualified professional, your local council or building control. Terms

Frequently asked questions

Reference guides for this task

Free guides to the tools, materials and terms this step involves.