Write a brief that can still change
Describe the space needed, intended use, access and acceptable disruption. This teaching scenario considers a possible 30 m² addition to an existing house in CDMX. It does not assume that the roof can carry another floor or that the proposed footprint and height are lawful. A smaller addition or a different arrangement may be the outcome of the investigation.
Collect ownership or possession documents, available plans, previous construction records and any condominium or shared-property arrangements. Have the appropriate advisers establish the right to carry out the proposal and the applicable planning constraints. A neighbour’s completed upper floor is not evidence that the same work is permitted or structurally possible on your property.
Assess the whole existing building
Ask the structural professional to assess the existing system, foundations, past alterations and the proposal’s effects. The CDMX construction regulation addresses structural modifications in relation to the building and foundations as a whole. Leave the required design, professional responsibilities and execution precautions to the appropriate registered team; there is no safe rule that a house of a certain age automatically supports an extra storey.
Identify access for inspection and whether investigation of the ground or hidden elements is needed. Do not select a structural method from a renovation article. Ask the team to state what is known, what is assumed and which finding would make the proposed scheme unacceptable or materially more expensive.
Confirm the procedure for this property
The Cuauhtémoc official procedure index distinguishes manifestations A/B/C, special licences and completion records. The applicable route depends on the work and property. The regulation also distinguishes qualified minor works from the notice arrangements that may still apply; “no special licence” does not mean “no procedure”. Check current documents, professional roles, land-use and heritage or conservation conditions with the competent authority.
Do this before a construction commitment. A 30 m² addition alone does not determine the category, fee or required team. Keep the written advice and actual decisions with the design. Other states and municipalities use their own rules; this CDMX scenario is not a national permit checklist.
Fund the first decision separately
The following invented MXN figures are final planning amounts including applicable supplier tax. They fund investigation and preliminary coordination, not construction. The ground/investigation allowance is provisional and does not prescribe a test. Authority-related advice is professional time, not an official approval fee.
| Line | Amount |
|---|---|
| Measured existing-condition survey | 4 500 |
| Structural assessment | 9 000 |
| Provisional ground/hidden-condition investigation | 6 500 |
| Preliminary architectural options | 8 000 |
| Service-capacity checks | 1 500 |
| Procedure advice and coordination | 2 500 |
| Subtotal | 32 000 |
| Technical-stage reserve: 10% | 3 200 |
| Initial-stage funding provision | 35 200 |
Build a conditional full-project model
Only if an appropriate design can proceed should you replace this initial model with coordinated scope and quotations. All construction, reinforcement and fee amounts below are hypothetical allowances, not a finding that reinforcement will be sufficient or that an approval will be issued. Keep the actual tax treatment of an extension separate from any assumptions used for ordinary renovation.
| Line | Amount |
|---|---|
| Provisional defined construction package | 330 000 |
| Initial feasibility provision above | 35 200 |
| Further detailed design outside first stage | 28 000 |
| Provisional official fees, not a tariff | 12 000 |
| Temporary accommodation | 9 000 |
| Temporary weather protection outside construction package | 12 000 |
| Service changes outside construction package | 32 000 |
| Making good the existing house | 26 000 |
| Provisional reinforcement outside construction package | 50 000 |
| Subtotal | 534 200 |
| Execution reserve: 10% of construction, services, making good and reinforcement | 43 800 |
| Conditional funding provision | 578 000 |
The execution reserve is 10% of a MXN 438,000 base; that base excludes the earlier technical-stage reserve and other non-work lines. The initial MXN 35,200 appears once. If an assessed reinforcement scope is priced at MXN 70,000 final, replace the MXN 50,000 allowance: preserving the fixed execution reserve gives MXN 598,000. Revisit its adequacy after the new scope; the example is not authority to build.
Approve the next commitment with evidence
- Confirm the property and planning position.
- Assess the existing building and proposal with the required team.
- Identify the procedure and obtain necessary decisions before work.
- Coordinate structure, services and temporary conditions.
- Replace allowances with defined, tax-aware quotations.
- Plan inspections and completion documents as part of delivery.
Keep a clear stop/go decision after feasibility. If the proposal cannot proceed, money spent on assessment is still a real project expense; the uncommitted construction allowance is not. That distinction prevents a preliminary budget from becoming a commitment before the house and the rules have been checked.
Sources, date and scope
- Consejería Jurídica y de Servicios Legales de la Ciudad de México — Reglamento de Construcciones para el Distrito Federal — texto vigente
- Alcaldía Cuauhtémoc, Ciudad de México — Ventanilla Única de Trámites — 2024–2027
Checked on 19 October 2026. Local examples concern Mexico City unless stated otherwise. All MXN amounts are invented calculation examples, not market prices or quotations. Each article describes an independent project. VAT is applied only under the example’s explicit assumptions; final amounts already include the applicable tax. Check diagnosis, design, procedures and contract conditions for the individual property with competent professionals.