How to judge a mansion: international homes by fit and quality

The first mistake people make with a large house abroad is judging it by home standards. A thick-walled house with small windows looks mean to someone raised among picture windows, until they spend a July afternoon inside.

A light timber house with a tin roof looks flimsy to someone raised among stone, until they see what stone does in an earthquake. A building is good or bad only in relation to the place it stands.

This page sets out how to judge international homes by fit and quality in a tradition you did not grow up in, and what to ask before taking a large mansion in another country seriously. It names the building traditions, records and authorities you can look up, then tests the criteria on three named houses in France, Mexico and Thailand. A mansion tour shows you surfaces and staging; these tests are about the parts a tour never reaches, and they apply to a landmark mansion and to an ordinary large house alike.

What to take away

Fit: the wall tells you the strategy

There are broadly two ways to build a comfortable house, and most of the world's traditions commit to one of them.

The heavy way uses mass: thick walls of stone, brick, earth or concrete absorb heat slowly by day and release it slowly at night. Adobe and rammed-earth houses in the hot, dry parts of the Middle East, North Africa and the American Southwest are the classic examples. The house lags behind the weather, which suits hot days with cool nights or long steady winters.

Windows stay small because every opening is a hole in the thermal store. Rooms are deep and ceilings high so air has somewhere to go.

The light way uses air. Thin walls, raised floors, wide openings, and a roof overhang far enough to keep sun and rain off the walls. Stilt houses across Southeast Asia and the Queenslander timber houses of subtropical Australia are built this way. The house stores no heat, lets the breeze through, and keeps rain out.

This is the strategy for humid climates, where mass would stay warm and damp, and for seismic regions, where a light frame flexes and survives what a heavy wall cannot.

Neither is better. The failure is the transplant: a heavy house where the place wanted air, or a glass box where it wanted mass.

Transplants are common in expensive houses because the design came from a photograph taken elsewhere. Mechanical plant can make them work, and that plant becomes the most fragile, most expensive part.

First question for any house abroad: which strategy does it use, and do its neighbors use the same one? If the answer differs from everything around it, find out why before you admire it.

The same test applies inside the United States, where a single style takes different forms by city, as described in the site's US homes by city guide.

Quality: look at the junctions

A house is made of surfaces, and surfaces are easy to make look good. It is also made of junctions, where water gets in, where movement shows, and where a builder's care is present or absent.

Guidance on how those junctions fail, and how they are repaired, material by material, is collected by the National Park Service in the Preservation Briefs series. The series was written for one country's stock, but its reasoning is general. Judge the junctions.

Roof to wall. Follow the path a drop of rain takes from the ridge to the ground. Is there an overhang, and is it deep enough for the local rain? Where does the gutter discharge, and does the water then get away from the base of the wall? A roof that dumps onto the ground beside the foundation is a slow-motion problem in any climate that has rain.

Wall to ground. Look at the lowest half meter of the wall, inside and out. Staining, blistered paint, crumbling plaster or a tide line of salts mean water is rising or splashing into the wall. Traditions that know their ground put a hard, water-resistant base course there, or lift the whole house clear of it.

Material to material. Where timber meets masonry, where a window frame sits in a wall, where an addition meets the original: these are the places a building moves, and a good builder allows for the movement. Cracks that follow a straight line along a junction are usually the two parts moving differently, which is normal. Cracks that run diagonally across a wall are something else, and a question for an engineer who knows the local ground.

The roof structure itself. Get into the roof space if you can. The timber or steel up there is the honest part of the building; it was never meant to be seen, so nobody dressed it up. Sagging members, patched repairs, daylight through the covering, and evidence of pests or damp all show here first.

Selection criteria

For someone comparing large houses across countries, the useful criteria are the ones that do not change with taste.

For the criteria in the table, none need a figure to answer. They need a walk round the building, a look in the roof, a local tradesperson's opinion, and a visit to whichever public body holds the records, whether that is a land registry such as HM Land Registry or the Grundbuch, a planning office, or a heritage authority.

Three international houses read against the criteria

Villa Savoye, Poissy, France. Le Corbusier and Pierre Jeanneret built this house between 1928 and 1931 with a flat roof and long ribbon windows. It is a famous case of a design that put looks ahead of the water path. The house was reported to leak early on, and the owners complained about it. Check the French Ministry of Culture's heritage database (Mérimée) for its protection record.

Casa Luis Barragán, Mexico City. The architect built his own house in 1947 and 1948. It presents a plain wall to the street and opens to a walled garden at the back, a layout that fits a mild, high-altitude city better than a large glazed front would. UNESCO lists it as a World Heritage property (inscribed in 2004), so protection status can be read in the public listing.

Jim Thompson House, Bangkok. The American businessman Jim Thompson assembled this compound in the late 1950s from traditional Thai teak houses, set on raised posts. This is the air strategy: raised floors, steep roofs with deep overhangs, and wood that a local carpenter can repair. The house shows how a hot, wet climate rewards a light frame.

Set side by side, the three show why the criteria are separate. The first scores well on design intent but badly on the water path. The second scores well on fit. The third scores well on climate strategy and local repairability. None of this replaces a survey, which is the only way to judge the quality of a house you might buy.

The paperwork is local everywhere

Three things about a house abroad can only be settled by the body responsible for them, and it is different in every jurisdiction.

Ownership is recorded in a land registry, cadastre or deed system, and these differ in what they guarantee. England and Wales have HM Land Registry, which registers title; Germany has the Grundbuch, a register of ownership and charges; France has the cadastre for parcels, while ownership is generally proven through notarial deeds. Some registers guarantee title; some only record that a document was lodged. Ask the registry itself, or a lawyer qualified in that country, what the record actually proves.

Protection is set by the planning or heritage authority. Systems vary, and reading one well-documented example makes the questions obvious: what listing on the National Register of Historic Places means sets out what such a status does and does not do. In England, Historic England maintains the National Heritage List for England and local planning authorities grant listed building consent; the list entry and the consent are the public forms to check.

A house may be protected in whole, in part, in its facade only, or through its setting within a protected area. The restrictions attach to the building and bind any owner, which is why they are public. Ask the authority for the current entry rather than relying on a description from anyone selling.

Condition is the job of a surveyor or engineer qualified where the building stands; a home inspection, step by step shows what that work involves. In many countries that means a member of RICS, the Royal Institution of Chartered Surveyors, or a national equivalent; a structural engineer should know the local seismic code, such as Eurocode 8 in the European Union. Building traditions are local, and a surveyor from one country will miss the standard failures of another. The right person is the one who has seen a hundred houses of this type in this climate.

This site has no view on any particular market and publishes no prices; the international homes list collects further notes. A mansion is an interesting building in any country, and the questions above are about the building itself, the part of it that photographs and tours never show.

Common questions

Why do large houses abroad often feel dark?

Because they were built for heat, and small windows are how a heavy house keeps cool. The darkness is the design working. Adding large openings without understanding the strategy turns a cool house into a hot one.

Is an old house always worse built than a new one?

No. An old house has been tested by many winters and summers, which is useful evidence, but survival alone does not prove sound condition; repairs may be hiding faults. A new house has not been tested yet. What matters is whether either was built for its place and whether the junctions have been kept up.

What is the single most useful thing to bring on a viewing?

A torch, for the roof space and the base of walls. The parts of a house that were never meant to be seen are the ones that tell the truth. In a very large house, where the service side was built to be hidden, that evidence is harder to reach and worth more.

How does a city house differ from this?

A city house has neighbors against two of its walls, and its problems are light and depth rather than climate and site. The two cases are set out in the site's New York homes interiors guide and, for the opposite condition of abundant land and a mild climate, in the site's Los Angeles homes list.