What is Technical Details Consent in Planning?
Learn what technical details consent is, how it follows a grant of permission in principle, what can be considered, and how the application and appeal process works.
PLANNING APPLICATIONS
Andrew Ransome
9/13/20263 min read
Permission in principle is a two-stage route to planning permission for housing-led development.
The first stage — permission in principle itself — establishes only whether a site is suitable in principle, looking at location, land use and the amount of development proposed. It can be granted either through a direct application to the local planning authority, or through a site being entered onto Part 2 of a council's brownfield land register.
The detailed design and technical details are considered in the second and final stage via the technical details consent (TDC).
This article covers that second stage in detail: what it assesses, how it's applied for, and what happens if it's refused.
What technical details consent is
Technical details consent is the second and final stage of the permission in principle route. Once granted, it has the effect of creating a full planning permission.
Development that has both permission in principle and technical details consent is simply described as having planning permission — the two-stage language falls away at that point.
A technical details consent application is assessed much like a standard planning application, but with one constraint: it must be in accordance with the permission in principle already granted for the site, and it cannot reopen the matters settled at that stage.
If permission in principle established a site as suitable for residential development, in a location, with a minimum and maximum number of dwellings, the technical details consent application cannot argue for a different use, a different site boundary, or a number of dwellings outside that range.
What technical details consent actually assesses
Everything that wasn't considered at the permission in principle stage falls to be assessed here:
Detailed design, layout and appearance
Access and highways
Drainage and flood risk
Ecology and biodiversity net gain
Heritage impact
Any other matter ordinarily relevant to a full planning application
The application must be supported by the same information a full planning application would require.
There's no reduced validation list at this stage, unlike at permission in principle.
One application, not several
A local planning authority cannot accept separate technical details consent applications for different phases of a site with permission in principle. A single technical details consent application must specify everything necessary to enable full planning permission to be granted for the whole permission in principle site.
If you're contemplating a phased scheme, this needs building into your strategy well before you reach TDC stage — it can't be resolved by submitting technical details piecemeal.
Planning Conditions and Obligations
Unlike permission in principle itself, where no conditions can be attached and no obligations can be secured — conditions can be imposed on a grant of technical details consent, subject to the usual tests of necessity, relevance, precision, enforceability and reasonableness.
Planning obligations can also be agreed at this stage, provided they meet the statutory tests, and Community Infrastructure Levy liability is triggered once technical details consent has been granted and development commences.
Application Timescales
Technical details consent applications carry the same statutory determination periods as any other planning application:
13 weeks for major development
8 weeks for minor development
16 weeks where the development is subject to Environmental Impact Assessment
A technical details consent application must be determined within the life of the permission in principle — 3 years for a direct application, 5 years where granted via the brownfield land register.
If technical details consent is refused
Refusal of technical details consent doesn't affect the underlying permission in principle.
A fresh technical details consent application can be submitted, provided the permission in principle hasn't since expired.
There's a full right of appeal against refusal, non-determination, or conditions imposed, following the same section 78 procedure as any other planning appeal. But in this instance an Inspector will explicitly treat the scope of the permission in principle as settled and not open to challenge.
The practical takeaway
Technical details consent is where the real cost and complexity of a scheme sits — the design work, the technical surveys, the consultant fees.
The advantage of the permission in principle route is that this investment only happens once the principle of development is secured, rather than upfront.
Getting the permission in principle stage right — a well-evidenced range of dwellings, a location that will support the scheme you actually want to build — makes the technical details consent stage far more straightforward.
Get Permission in Principle Advice
If you have a site with permission in principle and want advice on structuring or progressing a technical details consent application, get in touch with me to discuss further.
Andrew Ransome MRTPI - Email: andrew@andrewransome.co.uk
About me
Andrew Ransome is a Planning Director and a Chartered Member of the Royal Town Planning Institute (RTPI), with more than two decades of experience in town planning.
He specialises in delivering strategic planning solutions for complex developments across both rural and urban environments, helping clients navigate planning challenges and unlock development opportunities. Connect with Andrew on Linkedin.
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