Open almost any domestic full plans application and there is a sheet, or a column down the side of the section, headed "Building Regulations notes". It has been on every job the practice has done for years. It mentions Part L and Part F and the fire door to the garage. It was last read in full by whoever first wrote it.
Those notes are where the queries come from. Not because they are wrong, usually, but because they are generic: they describe a typical job, and the plan checker is looking at this one. The wall is a different construction. The roof is flat, not pitched. There is no garage. The note about the septic tank is on a house in a street with a public sewer. Each one is a question, and each question is a week.
What notes on a sheet cannot do
- Carry the working. A U-value on a drawing is an assertion. The calculation that produced it, layer by layer with the corrections for bridging and air gaps, does not fit beside a section and does not belong there.
- Be specific without being rewritten. A sheet of notes is edited by deletion, if at all. A specification is assembled for the job from the categories that apply, so the septic tank is not there to delete.
- State a single answer. Notes offer alternatives, because the same note has to serve every job: "80mm or 100mm depending on the perimeter ratio", "Celcon or Thermalite or equivalent". The specification is where the designer makes the choice and states it, so that nobody on site has to.
- Be revised. A specification carries a revision and a date. When building control asks for a change, revision P02 records it. A note on a sheet is changed silently, and the drawing sheet that carried it may not be reissued.
What the two should say about each other
Notes beside a detail stay beside the detail: the flashing, the cavity tray, the lintel bearing. The generic sheet is replaced by the specification. And the specification says, on its cover, that it takes precedence over any conflicting generic Building Regulations notes in the drawing pack, and that any discrepancy is to be referred to the designer before construction. That sentence costs nothing and ends an argument on site before it starts.
What a reviewer found in one issued specification. Flat roof falls stated the wrong way round, so the finished fall was steeper than the design fall meant to produce it. A floor offering two insulation thicknesses for the contractor to choose between. An internal quality-control heading, "verify before issue", printed on the issued document. Clauses for septic tanks, oil tanks, stoves, photovoltaics and wind turbines on a single-storey rear extension. None of it was on the drawings. All of it was in the notes that had travelled from job to job.
Every one of those is now impossible in the library this site describes, because each became a rule. That is what a maintained library is for.
The honest version of "template"
A template is a document you edit and hope you edited everywhere. A library is a set of clauses written once from the source, each checked against the Approved Document it comes from, with the date of the check recorded, and assembled for the project type so that only what applies is offered. The difference shows up at the plan check. It shows up again on site, where the specification is the document the contractor prices from and builds to, and a choice left open in it is a choice made by whoever is ordering the materials that morning.