Side Extension Questions

[freddiemercurystwin]

Many areas of Permitted Development are a bit grey, you will not get a categorical answer as to whether render is acceptable or not on here or from the planners under informal discussion. The only definitive way you'll get an answer is by submitting a Certificate of Lawful Development Application. Its pretty clear tbh that render finish is not similar to a brick finish but as previously mentioned if planners kick up you may be sticking some slips on.

 

[spongobongo]

The fundamental question is whether the use of render constitutes a material of "similar appearance to those used in the construction of the exterior of the existing dwellinghouse". Clearly, from the OP's first post, the use of render is an alien material.

So, for the purpose of submitting an application for a lawful development certificate, I'd show the side elevation being in brick so that there's no chance of getting the application turned down. Then, when you carry out the development, leave the blocks unrendered. You can then argue that your development is only part implemented and that your intention is to face the wall with bricks or brick slips. There is no provision* in planning law to make you complete a development within a certain time frame. The law is framed in terms of implementation not completion of development. Technically, the permission is implemented when you dig the first hole for the foundations.

If you render the wall, then you've deviated from the approved plans and your lawful development certificate is worthless. It would then be at the discretion of the local authority whether or not to pursue enforcement action.

[*that I've come across in ten years as a DC officer]