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Casa · Ampliación en altura · Málaga
Who builds the next floor (and holds up the hot tub)
Pros and cons of every firm on the shortlist for building the extension: heavy-steel fabricators, general contractors and envelope partners. The architect and the licence application are in hand and the proyecto de ejecución is the next deliverable, so this is about who executes the plans. Built from two research passes (three researchers each) on 14 September 2026, every link checked live.
Brief: hot-rolled steel beams (HEB/IPE) · concrete roof, precast or composite deck · energy-efficient outer walls · rooftop hot tub.
0 · Where we are
Básico done, licence in flight, ejecución next
Our architect has the proyecto básico drawn (June 2025) and is taking the ampliación through the Ayuntamiento as a licencia de obra mayor, first half of the fee paid July 2026. The básico is the licence document: plans, sections, elevations, surfaces. It does not contain the structure, the memoria or the mediciones. Those come in the proyecto de ejecución, which is the document builders quote against. So the engineering leg is not a separate hire, it is the architect's next deliverable.
✓
Básico + licence
Done and filed. New second floor of 61 m² (sala multiuso, bath, terrace) plus a 48 m² azotea with barbacoa above it.
1
Ejecución
Architect produces structure, memoria and mediciones. This is where the steel sizes, the deck type and the rooftop load get fixed.
2
Three quotes
Two or three constructoras, plus a taller if the ejecución is steel, all quoting on the same mediciones.
3
Contract + obra
Fixed price, payment by certificación, architect as dirección de obra, certificado final de obra at the end.
The pool on the roof is already drawn, the load is not yet calculated
The azotea at +11.00 carries a "previsión piscina hinchable" of roughly 2.5 by 2.5 metres, sitting directly over the new sala multiuso. Water is a tonne per cubic metre, so even a shallow inflatable pool is several tonnes, and a hot tub with people in it is in the same range on a smaller footprint. The básico shows the intent; the ejecución has to size the beams and the deck for it. Ask the architect to confirm that load is in the structural calculation, and whether swapping the inflatable pool for a permanent hot tub changes anything in the licence.
Four questions for the architect before the first builder call
1. When is the proyecto de ejecución due, and who does the structural calculation (him or a calculista)? 2. What structural system is he specifying: hot-rolled steel with a composite or precast deck, or concrete? That decides whether we need a taller at all. 3. Is the rooftop pool / hot tub load explicitly in the calc? 4. Mediciones y presupuesto as a spreadsheet, and which constructoras he recommends for ampliaciones in the city.
1 · Structural engineers · already covered
Kept for reference, not for calling
The structural calculation belongs to the architect's proyecto de ejecución, so none of these needs a call from us. They stay on the page for two reasons: if the architect subcontracts the calc or wants an independent check on the rooftop load, SBIT and CUMAR both publish exactly that capability; and each of them can name the talleres they trust for residential steel, which is the real gap in the fabricator list.
1
Structural engineer · calculista
Málaga capital
First call. Steel and concrete calcs for private owners reforming their house, with "adecuación estructural por cambio de uso o ampliación en edificios existentes" as a named service.
Pros
- Publishes the exact capability: reinforcement with perfiles laminados, refuerzo de forjados, ampliación of existing buildings.
- Residential track record on the coast: 23 villas with pools in Mijas, Meliá Don Pepe structural ampliación in Marbella.
- Local office in the city, WhatsApp-first contact.
- Works as the "external structures department" for owners and architects, so they slot in beside whichever architect we choose.
Cons
- Engineer only. Someone still has to build it.
- No rooftop-hot-tub or sobreelevación case published; it is inferred from the ampliación wording.
- No street address on the site.
Ask: fee for proyecto de estructura plus dirección de obra; which talleres they use for residential HEB/IPE with forjado colaborante; whether they have sized a rooftop jacuzzi before.
1
Structural engineer · calculista
C/ Francisco de Quevedo 4, Marbella
Exact stack, verbatim. Their services page literally lists "Estructuras metálicas con forjados colaborantes", "Cálculo de refuerzos de estructuras" and "Estructuras de viviendas aisladas, adosados".
Pros
- The only engineer whose site names steel plus composite deck for houses in so many words.
- Reinforcement calcs and pathology of concrete and steel structures listed, useful if our existing slab needs help.
- Ampliaciones portfolio on the coast: ático in Edificio Tempo (Puerto Banús), Piscina Casa Medina (Marbella), a water-tank structure in El Palo, villas in Las Chapas and Mijas Golf. Water loads on structures are familiar ground.
- Small practice, so the person who answers the phone is the one doing the calc.
Cons
- Marbella office, an hour away; confirm they take Málaga-capital work.
- Site is thin on technical detail; the portfolio is a list of names, not case studies.
Ask: two residential composite-deck projects we can see; turnaround for a calc with visado; whether they do dirección de obra in the city.
2
Structural engineer · calculista
Málaga / Torre del Mar (Alejandro Catapano)
Solid second option. "Cálculos de estructuras para obra nueva, rehabilitación, ampliación y refuerzo estructural" in concrete, steel and mixed systems, to CTE and Eurocodes.
Pros
- Ampliación and refuerzo named explicitly; mixed steel-concrete systems in scope.
- A named Málaga engineering director with a direct number.
Cons
- Distributed firm (Valencia, Barcelona, Baleares); make sure the Málaga engineer owns the job.
- No residential project pages to inspect.
Ask: who signs the calc and who visits site; examples of small residential ampliaciones.
2
Structural engineer · calculista
C/ Trinidad Grund 4, Málaga
The heavyweight. Thirty-plus years in the city, single-family houses through to bridges and civil works.
Pros
- Deep bench, 3D modelling, decades of Málaga licences behind them.
- Central office, easy to sit down with.
Cons
- Civil-works profile; may price a one-house job high or push it down the queue.
- Page does not mention steel or refuerzo specifically.
Ask: whether they take residential ampliaciones this size and what a fixed fee looks like.
3
Structural engineers · backup options
Málaga (Trévenez) · Alhaurín de la Torre · Málaga · Fuengirola
Backups. CQD is an established Málaga engineering office (villas in Benahavís and Marbella on its projects page). Vespro in Alhaurín publishes structural calcs for batches of 36 and 22 unifamiliares. CESCAL lists reforma, rehabilitación and refuerzo in steel and concrete. Yolanda Alarcón is a one-person practice in Fuengirola since 1994, likely the lowest-cost stamped calc.
Pros
- All four are local and do residential work; CQD and Vespro have volume villa experience.
- Alarcón: independent, fast, cheap for a load report.
Cons
- No named ampliación or rooftop-load projects for any of them; CQD and Vespro read concrete-first.
- Alarcón: single person; check capacity and whether she does dirección de obra.
Ask: a fee quote for comparison against SBIT and CUMAR.
2 · Heavy-steel fabricators
Who bends the big beams
The residential heavy-steel market in Málaga is nearly invisible online: the talleres photograph naves and entreplantas, not house extensions. None of these publishes a residential HEB/IPE storey addition. Only needed if the proyecto specifies steel. Brief them with the architect's drawings and mediciones and ask every one for photos of a residential forjado on steel; that single question sorts the fabricators from the pergola shops.
1
Fabricator · erector
Málaga capital; serves Marbella, San Pedro, Estepona
Best local taller match. The first pass filed them as industrial; their estructuras page actually lists "viviendas y edificios residenciales" and "ampliaciones de terrazas, cubiertas y cerramientos", plus entreplantas, forjados and pilares with CE marking.
Pros
- Design, fabricate and erect under one roof; CE-marked structures.
- Residential and terrace ampliaciones named on the page.
- Local, established, answers the phone.
Cons
- No HEB/IPE or composite-deck wording and no residential gallery.
- Also does railings, gates and awnings; check the structural crew is a real one.
Ask: two residential forjado-on-steel references with photos; whether they pour the deck or subcontract it.
1
Structural-steel constructor
Pol. Guadalhorce, Málaga
The biggest local structural-steel builder. New-build steel for "edificios comerciales, residenciales o industriales" and "reestructuración" of existing structures (Guardia Civil, the TSJA court building).
Pros
- Serious structural capability, big-project references, modifies existing structures.
- Workshop in the city; no travel premium.
Cons
- Profile is institutional and industrial; a single house may be too small for them.
- No residential gallery.
Ask: whether they take a single-house sobreelevación at all; if yes, a quote against the engineer's drawings.
2
Fabricator · erector
Arenas 43, Vélez-Málaga
The one taller that says "lámina colaborante". Houses, buildings, bridges, composite-deck slabs and mezzanines; project cards include a full ático dúplex structure and a suspended steel balcony.
Pros
- Names composite deck explicitly, which nobody else local does.
- Residential pieces in the portfolio (ático, balcony), since 2012.
Cons
- Axarquía, around 40 minutes out.
- No in-house calc; contact details buried behind a form.
Ask: photos of a residential composite deck they have done; lead time for fabrication.
2
Fabricator · benchmark quote
Los Villares, Jaén (about two hours)
The only verified page with our exact stack in Málaga: "ampliación de entreplanta consistente en pilares y vigas metálicas con forjado colaborante (Málaga)". Use them to keep the local quotes honest.
Pros
- Proven identical work, in this city, on a published project page.
Cons
- Out of province; transport and montaje logistics add cost and friction on a small job.
Ask: a quote for benchmarking; whether they still take Málaga work.
2
Fabricator · erector
C/ Genal 19, Pol. El Fuerte, Ronda (about 90 minutes)
The one that names hot-rolled profiles and composite decks. "Perfilería normalizada" and "forjados compuestos: estructura metálica y una chapa perfilada" for edificación, 35-plus years in business.
Pros
- Exactly our structural vocabulary, on their own site, in the building (not just nave) section.
- Long-established with its own steelworks.
Cons
- Ronda is a real drive; montaje days cost more.
- No residential storey addition shown.
Ask: whether they erect in Málaga city and what a small residential job costs them in travel.
3
Steel-structure rehab contractor
Periana (Axarquía)
Steel-led rehab in the city centre. Positions itself as "rehabilitación de edificios y viviendas basada en estructuras metálicas" and has a published partial rehab (façade, roof, interior redistribution) of a residential building in central Málaga.
Pros
- Residential rehab in Málaga centro on a real project page.
- Steel structure is the firm's stated core, not a sideline.
Cons
- Project page gives no structural detail; the storey-addition question is open.
- Periana base, over an hour out.
Ask: what the Málaga-centro job's structure was and whether they have done an elevación de planta.
3
Steel broker · network
National, Málaga landing pages
Right words, no address. The most explicit residential heavy-steel copy found (IPE/HEB/HEA, replacing load-bearing walls with beams, reinforcing forjados, HEB columns with composite deck), but it is a lead-router with no Málaga workshop or phone.
Pros
- Describes exactly the work; 48-hour technical response promised.
Cons
- Broker, not a taller; we would be paying a margin to reach a local shop we could call directly.
Ask: who the Málaga taller is, then quote them directly.
4
Also on the listNew
Smaller talleres and erectors
All claim residential steel; none shows it. Worth a call only if the top four cannot quote. CAF's cranes are useful for lifting beams onto a roof in a tight street.
3 · General & structural contractors
Who runs the whole job
Two firms have actually added a storey to a house in Málaga. Neither advertises our structural system, so the question for each is whether they will build to the architect's plans and quote on his mediciones. If Baupanel's panel system is not what the proyecto specifies, they drop out unless the architect is willing to re-spec.
1
General contractor
Avda. Andalucía 23, Málaga · Estación de Cártama
Doing it right now. A live reforma integral "con elevación de planta" on a unifamiliar in central Málaga (Coto de Doñana 14), plus structural reinforcement jobs in Mijas and Fuengirola.
Pros
- The only local contractor with a published storey addition, in progress, in the city.
- Knows the Málaga licence process and has refuerzo estructural experience.
- A site we could ask to visit.
Cons
- Structural system unstated; their Mijas and Fuengirola refuerzos used carbon fibre, not steel.
- No steel, precast or SATE wording anywhere on the site.
Ask: what structure is going on Coto de Doñana and which taller is fabricating it; whether they will build steel plus deck to our engineer's spec.
1
Contractor with its own panel system
Torremolinos office · Antequera factory
The alternative worth quoting. Three named storey additions in the province (Málaga 2017, Benahavís 2018, Málaga 2019) using their EPS-core reinforced-concrete panel system rather than steel.
Pros
- Dated, named storey additions here; nobody else has that.
- Light: their slab is about half the weight of a traditional one, easier on our existing walls.
- Envelope insulated by design; claims roughly 40% better thermal performance than traditional build.
- Factory in the province, one firm for structure and walls.
Cons
- Not steel beams plus concrete deck; it is a monolithic shotcrete panel system, so the hot-tub zone would need its own engineered solution.
- Proprietary: future modifications depend on them.
Ask: the three Málaga references; how they would carry a rooftop hot tub; a quote on the same brief so we can compare weight, cost and thermal numbers against the steel route.
3
Structural contractors, concrete-led
Mijas Costa · Maqueda, Málaga
The precast half of the brief. MAD's gallery shows a 30+10 forjado of placas alveolares on 80 cm deep beams; La Costa runs its own ferralla shop and lists a Marbella villa and twelve unifamiliares.
Pros
- Both build slabs and structure daily; both can execute a steel-plus-deck design.
- MAD has hollow-core precast experience on villas.
Cons
- Concrete-led; steel would be subcontracted.
- Neither shows a storey addition.
Ask: whether they would act as main contractor with a steel taller underneath them.
3
General contractor
Antequera
Backup. Documented steel-frame annex on a rehab job and a reforma-y-ampliación in Sotogrande.
Pros
- Comfortable with steel and with ampliaciones; villa-grade finish.
Cons
- Their cited jobs are in Córdoba and Cádiz, not Málaga; no vertical-extension page; Antequera base.
4 · Envelope & architects
The efficient walls and the licence
We already have an architect, so ZEB and MB are only relevant if we want a second opinion on the wall build-up. Aryon is the builder to bring in if the envelope target is Passivhaus-grade and the proyecto allows it.
2
Architects · Passivhaus certified
Coín · Málaga capital
Licence plus envelope in one. ZEB are certified Passive House Designers who favour industrialised dry construction; MB is a Málaga-capital studio offering Passivhaus certification and PHPP modelling.
Pros
- Both can write the licence file and specify SATE or an equivalent efficient wall.
- MB is in the city; ZEB's dry-construction preference fits a steel structure.
Cons
- Neither mentions ampliación or sobreelevación on their site.
- ZEB is in Coín and split with Barcelona.
Ask: storey-addition experience, fee structure, and whether they are happy working with our chosen calculista rather than their own.
3
Envelope · Passivhaus builder
La Cala de Mijas
Best walls on the coast. Built Villa Suasana in Mijas, the first Passivhaus Premium in Andalucía (concrete structure plus SATE), with a Passivhaus Tradesperson-certified crew.
Pros
- Proven, certified, energy-efficient envelope work; SATE crew in house.
Cons
- No storey-addition or steel track record; a partner for the walls, not the structure.
- Mijas, not the city.
4
Recalce · foundations, only if needed
Estepona
Resin-injection recalce, micropiles, concrete repair and diamond cutting of slabs. Only enters the picture if the calculista says the foundations or the existing slab need help.
5 · Demoted after the hot-tub requirement
Right idea, wrong steel
Both firms below have actually added a floor to a house on the coast, which is why they led the first pass. They work in light-gauge galvanised steel framing, sized for lightness. A wet point load of a tonne or more is the opposite brief.
–
Light-gauge steel frame
Toledo HQ; built an added floor in Calahonda (Mijas)
Pros
- Real storey addition on a beachfront house in Mijas, published.
Cons
- Light steel frame, not HEB/IPE. No Málaga office. No envelope language.
–
Light-gauge steel engineering
Málaga
Pros
- Local engineering and fabrication; offers reinforcement over existing structures.
Cons
- Light gauge only; no storey-addition portfolio.
Where the sheet lives
The working tracker with every firm, phone, evidence link, status and call notes is a private Google Sheet ("Ampliación casa — constructoras shortlist"). This page is the readable version; the sheet is where the calls get logged.