Loft Conversion Plans - City Lofts London

Mini-guide on how to get your loft conversion plans off the ground

What are loft conversion plans?

Loft conversion plans are a set of architectural drawings and calculations produced with the purpose of designing a loft conversion, which complies with both local authority planning protocol and that also meet all relevant building regulations.


Why do I need loft conversion plans?

You will need loft conversion plans in place in order to get your loft conversion built.

Prior to starting building work, you must first obtain either planning permission or a certificate of lawfulness from the local authority, depending on your circumstances.

In order to obtain these you will first need to produce and submit a set of loft conversion plans that outline to the Planning Officer exactly what you intend to build, and describe to the Building Control Inspector exactly how you intend to build it.

loft conversion plans

loft conversion plans

What do loft conversion plans comprise of?

Loft conversion plans comprise of three constituent parts.

  • Planning level output. This is a simple but precise set of drawings designed to show the local authority what you plan to build. The local authority are only concerned with what the loft conversion will look like from the outside and how it will impact the street scene. Planning level drawings show the before and after views of your home from all aspects. It is these loft conversion plans that are submitted to the planning office in order to obtain planning permission/certificate of lawfulness for your loft conversion.
  • Building control level output. This portion of your loft conversion plans, are effectively the blueprints for your loft conversion. They build upon the planning level drawings, detailed exactly how the loft conversion will be constructed and using what material. Your assigned Building Control Officer will review and approve this portion of the loft conversion plans and issue an ‘initial notice’ signaling that he/she is happy for construction to start.
  • Structural Engineering output. Your assigned Structural Engineer produces this final portion of the loft conversion plans. Structural calculations are a set of mathematical proofs (that can run into several dozen pages), which describe how the Engineer has decided upon the final structural arrangement for the loft conversion, including steel beam configuration, beam types and beam sizes.
loft conversion map

loft conversion map

How do I get my loft conversion plans?

To get going with your loft conversion plans, you can either hire a professional specialist design and build firm, or hire a recommended Architect.

An Architect will typically charge a variable fee between 5%-10% of the project total for their services. The cost uncertainty of high, non-fixed fees does not suit all people however.

Some may instead prefer the low, fixed fees of firms like


Need more info on your loft conversion plans? Get in touch / Or call 02088988299 Mon-Fri 9am-5pm

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