The arithmetic of thirty doors

Buying one apartment entrance ends in three decisions: model, size, price. Buying thirty across ten blocks keeps those three and adds six more: dimensional variation, delivery sequence, installation programme, keying, spares and acceptance criteria. What makes bulk buying hard is not the quantity, it is that those six depend on each other.

Survey: thirty openings, thirty sets of figures

Even in one development, with blocks cast from the same formwork, entrance openings do not come out identical. Plaster thickness, formwork tolerance and floor level shift by a few centimetres from block to block. The most expensive mistake in a bulk order is measuring one opening and applying it to thirty.

Measure each opening separately: width at bottom, middle and top, height at three points, wall thickness at both jambs. Put those figures in a table keyed to block numbers. Production is planned from that table, with standard frames where the numbers cluster and a purpose-made frame where one block sits apart.

If the shell is still going up, one more decision waits: measure now, or after plaster and screed? The second always gives better figures and always squeezes the programme. The usual compromise is to start production from the rough figures and specify adjustable frame depths.

Delivery follows the installation programme

Thirty doors arriving on one day creates a storage problem. Stacked flat, leaves press on each other; left upright, they can topple; kept outdoors, the packaging takes up moisture. So delivery is split into batches matching the installation programme: the blocks ready for fitting that week get their doors that week.

There is a second benefit. Doors delivered early sit in an unfinished site exposed to knocks and dirt. The later a door arrives, the lower the risk of damage before handover.

Keys and locking

Keying is the most commonly skipped item in a bulk order. If the management office is to open every block entrance with one master key, the cylinders have to be produced to that plan, and the plan is set at order stage. Introducing a master suite afterwards means replacing every cylinder.

Electrified hardware is the second decision. Where blocks share one intercom infrastructure, matching the door-side hardware across the project simplifies both spares and service. The cable route through the frame profile is planned in production too.

Where standardisation stops

The economics of bulk buying come from standardising: one leaf size, one pattern, one surface, one lock. Yet some blocks face a different direction, sit under a different canopy or carry a different escape requirement. The practical approach keeps composition and surface fixed across the project and varies only frame depth, swing direction and hardware block by block. The elevations stay coherent and the technical requirement is still met.

Write down the acceptance criteria

  • Dimensional tolerance on leaf and frame, and what deviation is accepted.
  • What counts as a surface defect: scratch, tone variation, visible joint.
  • Evenness of the leaf-to-frame gap all round.
  • The door neither drifting open nor closing under its own weight.
  • Bolts entering the keeps without force.
  • Packaging intact on delivery, and the window for reporting damage.

With those lines in the order, handover stops being a negotiation. Both sides know what is being checked.

Spares and service

Across thirty doors and several years, handles break, gaskets harden and closers drift out of adjustment. Buying a small spares package with the delivery saves the committee hunting for the same model two years later: a few sets of handles, a run of gasket, a couple of closers and some cylinders. It is a small line in the budget and a large convenience later.

What to send with a request

A measurement table by block, the swing and escape status of each entrance, the surface and composition wanted, the keying plan, the electrified hardware list, the installation programme and the delivery address. With all of that in one place the project can be priced in one pass; a price built on partial information has to change during production.

Choose your schedule from building entrance doors and send it with your measurement table. Independent villa entrances from glazed villa steel doors and stair or escape exits from fire doors can be priced within the same quotation.