A large residential remodel in Mexico follows a design process that is more complex than a new build, not simpler. The existing structure introduces constraints that must be diagnosed before design begins — and that diagnosis determines whether the project is feasible, what it will cost, and which design options are actually available.
Phase One: Site Diagnosis
The site diagnosis is a paid engagement, separate from the design contract. It takes two to three weeks and produces a document that the client owns regardless of whether the design proceeds.
The diagnosis covers four areas:
Structural assessment. The existing foundations, columns, bearing walls, and slabs are surveyed and evaluated for load capacity. In Mexico City, homes built before 1985 require particular attention — the earthquake seismic record of the city means that unreinforced masonry structures in many colonias have accumulated damage that is not visible on the surface. A structural engineer is part of the diagnosis team.
Installation survey. Plumbing, drainage, electrical, and gas systems are mapped and age-evaluated. Large homes that have been occupied for decades typically have installations from multiple contractors and multiple eras — overlapping systems that interact in ways no single plan documents. The diagnosis traces the actual configuration, not the original drawings.
Program evaluation. The client's desired program is tested against the existing structure. Which elements of the program can use existing spaces without structural modification? Which require demolition and reconstruction? Which are feasible but expensive? This evaluation sets up the options for the design phase.
Normative review. Mexico City's delegaciones and alcaldías have specific requirements for construction permits on existing structures. Heritage protection zones — many of the most desirable residential areas of CDMX are partially or fully protected — impose additional constraints. The diagnosis identifies these constraints before design investment begins.
Phase Two: Matrix of Options
The diagnosis phase ends with a matrix of options: two or three clearly defined intervention scopes, each with its spatial implications, structural requirements, installation implications, and cost range. This is not a design presentation — it is a decision framework.
Option one might be a cosmetic and installation renovation that keeps the structural configuration intact and focuses on material quality and spatial detail. Option two might add a structural intervention that removes a bearing wall to open the main social area, at a significantly higher cost. Option three might combine the renovation with a new addition on the rear of the lot.
Each option is presented with the same level of information: what it does, what it costs to design and build, what it requires in permits, and what it cannot do given the existing structure. The client selects based on their budget, their program priorities, and the timeline they have available.
Phase Three: Schematic Design
Once the matrix option is selected, schematic design develops the chosen scope into a spatial proposal. At this phase, the design shows:
- Plan organization of the modified structure.
- Section through the key interventions — where walls are removed, where additions are added, how ceiling heights change.
- Material concept for the primary surfaces.
- Integration strategy: how new construction relates to existing fabric, whether through deliberate contrast or continuity.
The section as narrative is especially important in remodel projects. The section shows how the existing structure and the new intervention coexist — which elements are retained, which are modified, which are new. This reading is what gives a remodel project its architectural coherence.
Phase Four: Design Development
Design development translates the schematic into a detailed material and detail specification. At this phase:
- All materials are specified at a level sufficient for contractor pricing.
- Custom details — built-in furniture, window and door details, stair design — are drawn at a larger scale.
- Structural modifications are coordinated with the structural engineer and resolved in the drawings.
- Mechanical and electrical systems are designed around the new program.
Phase Five: Construction Documents and Permits
The construction documents package for a large residential remodel in Mexico includes:
- Architectural plans with dimensions and notes sufficient for construction.
- Structural drawings signed by a licensed structural engineer.
- Mechanical, electrical, and plumbing plans.
- Material and finish specifications.
- Bill of quantities for contractor bidding.
- Permit drawings in the format required by the relevant alcaldía.
The permit process in Mexico City runs in parallel with construction document completion. Permit approval times vary by alcaldía and by the type of intervention — structural modifications in normal zones take three to eight weeks; interventions in heritage zones take longer.
Próximos Pasos
If you are considering a large residential remodel in Mexico City and want to understand what it will actually take before committing, the diagnosis phase is the correct first step. It converts an uncertain undertaking into a defined project with real options and real costs.
Conoce el método de MÉTODO to understand how the design process unfolds from diagnosis through construction.