Farre+Stevenson Architecture provides measured architectural surveys and existing-condition documentation for renovation, due diligence, adaptive reuse, historic buildings, interior projects and landscape design. The purpose of a survey is to create a reliable geometric and descriptive basis for design, technical assessment and comparison with available planning and archival documents.
An architectural survey is not simply a collection of individual dimensions. It requires a coherent system of measurements, reference levels, control points, photographs and observations capable of describing how the building or site is actually configured.
The methods, instruments, accuracy and deliverables are defined according to the characteristics of the property and the intended use of the survey. A preliminary residential survey requires a different level of investigation from the documentation of a historic building, an irregular roof, a façade or a complex landscape site.
Surveying existing buildings
Existing buildings often differ from available drawings because of construction tolerances, undocumented alterations, settlement, deformation or incomplete historical records.
A measured survey may record:
- internal layouts and room dimensions;
- wall thicknesses and principal construction elements;
- doors, windows and other openings;
- stairs, ramps and vertical connections;
- floor levels and ceiling heights;
- balconies, terraces, roofs and external areas;
- façades and architectural details;
- visible structural elements;
- service shafts, plant spaces and principal equipment;
- significant irregularities or differences from available drawings.
A reliable basis for architectural design
Design decisions should be based on the actual condition of the property rather than on assumptions or outdated drawings.
A survey can support:
- renovation and internal reorganisation;
- restoration and conservation;
- extensions and additions;
- change-of-use studies;
- interior architecture;
- building-services coordination;
- structural assessment;
- planning applications and technical reports;
- BIM and HBIM modelling;
- cost planning and construction documentation.
Preliminary review before the site visit
Where available, the survey is prepared through an initial review of existing documentation.
This may include:
- approved architectural drawings;
- historical plans and archival records;
- cadastral plans;
- previous surveys;
- structural drawings;
- building-services documentation;
- photographs and property information;
- documents identifying the intended scope of the project.
This preliminary review helps identify the areas that require particular attention and the discrepancies that should be checked on site.
Measured floor plans
Floor plans document the horizontal organisation of the property and the relationship between spaces, walls, openings and circulation.
The survey may record:
- overall and internal dimensions;
- wall thicknesses;
- door and window positions;
- structural grids and columns;
- stairs and changes of level;
- fixed furniture and significant built-in elements;
- sanitary fittings and principal equipment;
- service shafts and visible installations;
- room names and uses;
- reference levels and ceiling heights.
The amount of information represented is selected according to the intended use of the drawings. Excessive detail can make the survey difficult to read, while insufficient information may make it unsuitable for design or verification.
Sections and vertical measurements
Sections are essential where the building contains different floor levels, complex roofs, stairs, vaulted spaces, mezzanines or irregular internal heights.
Section surveys may document:
- floor-to-floor heights;
- finished floor and structural levels;
- ceiling and roof profiles;
- stairs and landings;
- vaults, beams and soffits;
- windows and door heights;
- balconies and external levels;
- relationships between interior and exterior spaces;
- visible construction thicknesses;
- changes of level and local deformation.
Elevations and façade surveys
Façade surveys may be required for restoration, maintenance, external alterations, window replacement, planning documentation and the study of architectural proportions.
The documentation may include:
- overall façade dimensions;
- window and door openings;
- cornices, balconies and projections;
- roof edges and parapets;
- materials and visible finishes;
- downpipes and external services;
- decorative and historic elements;
- visible cracking, detachment or deterioration;
- relationships with adjoining buildings;
- photographic or photogrammetric rectification.
Level surveys
Accurate knowledge of levels is important for refurbishment, accessibility, drainage, landscape design and coordination between rooms and external areas.
A level survey may record:
- finished floor levels;
- thresholds and steps;
- internal height differences;
- balcony and terrace levels;
- external ground levels;
- slopes and gradients;
- drainage points;
- retaining walls and changes of terrain;
- relationships between the building and surrounding open space.
All levels should be related to a clearly identified reference datum. Where appropriate, the survey may also be connected to an established topographic or geographic reference system.
Surveying stairs and complex geometry
Stairs, ramps, vaulted spaces, curved walls, irregular roofs and historic construction frequently require more than simple linear measurements.
The survey may combine:
- direct measurement;
- diagonal control dimensions;
- angle measurements;
- level data;
- photogrammetry;
- point-cloud acquisition;
- three-dimensional reconstruction;
- additional control points for verification.
The selected method depends on the geometry, accessibility and accuracy required.
Laser distance measurement
Laser distance meters are useful for the rapid and accurate acquisition of dimensions within buildings and accessible external areas.
They may be used to measure:
- room dimensions;
- diagonals and control distances;
- heights and indirect dimensions;
- openings and wall positions;
- distances between reference points;
- selected external dimensions.
Laser measurements remain subject to visibility, reflective surfaces, obstructions, instrument position and correct interpretation. They are therefore integrated with sketches, photographs and redundant control measurements.
Total-station and topographic surveying
Where greater geometric control or external coordination is required, a total station or other topographic equipment may be used directly or through specialist surveyors.
This can support:
- building footprints;
- façade control points;
- external levels and terrain;
- property and site features;
- relationships between separate buildings;
- large or inaccessible spaces;
- connection with an established coordinate system;
- verification of alignment and deformation.
Legal boundary surveys and cadastral boundary determinations are undertaken by professionals specifically qualified for those services where required.
Photogrammetry
Photogrammetry reconstructs geometry from a controlled sequence of overlapping photographs. It can be useful for façades, decorative elements, irregular surfaces, roofs, interiors and landscape features.
The process may produce:
- scaled photographic documentation;
- orthophotos;
- point clouds;
- three-dimensional meshes;
- surface models;
- textured digital records;
- data for CAD, BIM or HBIM development.
The quality of the result depends on image coverage, lighting, surface texture, camera calibration, access and the presence of appropriate scale and control information.
Point clouds
Point clouds provide a three-dimensional record composed of a large number of measured points. They can support the documentation of complex buildings and sites.
Point-cloud data may be used for:
- checking dimensions and geometry;
- producing plans, sections and elevations;
- recording irregular or deformed surfaces;
- modelling historic architecture;
- survey-to-BIM workflows;
- comparison between existing conditions and design;
- digital archiving of the surveyed state.
A point cloud is not automatically a completed architectural survey. It requires registration, control, interpretation and conversion into appropriate drawings or models.
Historic-building surveys
Historic buildings often contain irregular geometry, stratified construction, deformation and traces of previous alterations that should not be simplified without consideration.
The survey may document:
- non-orthogonal walls;
- variable wall thicknesses;
- vaults and complex ceilings;
- historic openings and later modifications;
- construction joints and changes in materials;
- decorative elements;
- visible deterioration;
- different phases of construction;
- uncertainties that require further investigation.
The purpose is not to force the building into an idealised geometry but to represent the characteristics relevant to conservation, design and understanding of its construction history.
Surveying for renovation projects
Renovation requires reliable information about the relationship between existing spaces, structures, services and proposed works.
The survey may support:
- demolition and proposed-work drawings;
- internal redistribution;
- new openings and connections;
- coordination with structural engineers;
- building-services layouts;
- kitchen and bathroom design;
- custom furniture and joinery;
- material quantities and cost planning;
- comparison with approved documentation.
Surveying for technical due diligence
In technical due diligence, the survey provides an objective basis for comparing the property with planning, building and cadastral records.
It may help identify:
- different internal layouts;
- changes to openings or façades;
- additional floor area;
- altered balconies or terraces;
- mezzanines and changes of height;
- different property boundaries;
- undocumented works;
- dimensional discrepancies requiring further assessment.
The survey records physical conditions; the legal significance of each discrepancy must then be assessed through the applicable planning and building framework.
Surveying for BIM and HBIM
Measured information can be converted into an architectural BIM or HBIM model where this is part of the agreed commission.
The survey-to-BIM process may include:
- definition of coordinates and levels;
- review of source data;
- modelling of principal architectural elements;
- classification of existing components;
- integration of point clouds and photographs;
- representation of irregular geometry;
- identification of uncertain or inaccessible elements;
- production of model-based plans and sections.
The required geometric and informational detail must be defined before modelling begins.
Landscape and garden surveys
Outdoor-space projects require an understanding of both built and natural features.
A landscape survey may include:
- building footprints and external walls;
- paths, paving and steps;
- ground levels and slopes;
- retaining walls and boundaries;
- trees and significant vegetation;
- drainage points and visible services;
- terraces, patios and garden structures;
- views and relationships with surrounding buildings;
- areas of sun, shade and exposure.
Detailed arboricultural, topographic or boundary surveys are coordinated with the relevant specialists where required.
Roof and terrace surveys
Roofs and terraces may require specific documentation for waterproofing, drainage, maintenance, structural review or proposed alterations.
The survey may record:
- roof geometry and slopes;
- ridges, valleys and eaves;
- parapets and perimeter elements;
- drainage outlets and rainwater routes;
- chimneys, equipment and penetrations;
- terrace levels and thresholds;
- visible defects and areas of deterioration;
- relationships with adjoining roofs and façades.
Access and safety conditions must be evaluated before any roof survey is undertaken.
Photographic documentation
Photographs are an essential part of the survey record and help relate measurements, drawings and visible conditions.
Photographic documentation may include:
- general views of each space;
- numbered viewpoints linked to drawings;
- architectural details;
- materials and finishes;
- visible defects;
- services and equipment;
- external areas and façades;
- reference scales and control points.
Photographs do not replace measurements but provide important evidence for interpretation and later project development.
Accuracy, tolerance and purpose
No survey is infinitely precise. Every measurement is affected by the instrument used, the conditions of access, surface irregularity, visibility and the method of acquisition.
Before work begins, the survey requirements should define:
- the purpose of the survey;
- the areas to be measured;
- the required level of accuracy;
- the level of drawing or modelling detail;
- the reference datum and coordinate system;
- the instruments and methods to be used;
- the required deliverables;
- known access limitations;
- elements excluded from the commission.
The survey should be proportionate to the decisions it is intended to support. A model for conceptual renovation does not require the same tolerance as fabrication, structural monitoring or specialist conservation work.
Control measurements and error checking
Reliable surveying requires checks that identify inconsistencies before drawings or models are issued.
Control methods may include:
- overall dimensions;
- diagonal measurements;
- closed measurement loops;
- repeated levels;
- comparison between adjoining spaces;
- redundant control points;
- comparison with point-cloud or photographic data;
- review of geometric inconsistencies during drawing production.
Where measurements conflict, the discrepancy should be investigated rather than hidden through graphic adjustment.
Survey limitations
A measured architectural survey records accessible and observable conditions within the agreed scope.
Unless expressly included, it does not establish:
- legal property boundaries;
- structural capacity or safety;
- the condition of concealed services;
- the composition of hidden walls or floors;
- the presence of hazardous materials;
- the completeness of public records;
- the legal status of identified discrepancies;
- conditions within inaccessible or unsafe areas.
Where necessary, the survey identifies matters requiring structural, cadastral, geotechnical, environmental or other specialist investigation.
Existing-condition drawings
Survey information may be issued as a coordinated set of existing-condition drawings.
Depending on the commission, these may include:
- floor plans;
- roof plans;
- reflected ceiling plans;
- sections;
- internal and external elevations;
- level and slope diagrams;
- detail drawings;
- photographic sheets;
- comparison drawings;
- three-dimensional views.
Digital deliverables
Deliverables are agreed according to the intended use of the survey and the software environment of the project team.
Available outputs may include:
- PDF drawings;
- DWG and DXF files;
- two-dimensional CAD drawings;
- BIM and HBIM models;
- IFC files;
- point clouds;
- three-dimensional meshes;
- orthophotos;
- images and photographic records;
- measurement tables and schedules;
- agreed open or exchange formats.
Digital files should be checked after exchange because scale, coordinates, line types, layers, classifications and model information may not transfer identically between different software platforms.
Survey records and traceability
For complex projects, the survey should retain sufficient information to allow measurements and interpretations to be reviewed later.
The record may include:
- field sketches;
- measurement files;
- instrument data;
- photographs;
- reference points and datums;
- notes concerning inaccessible areas;
- assumptions used in drawing production;
- revision history of the issued survey.
International and remote commissions
Farre+Stevenson works with Italian and international clients and can provide survey documentation in English.
For clients based abroad, the service may include:
- coordination of access to the property;
- site inspection and measured survey;
- English-language drawings and reports;
- online presentation of the findings;
- coordination with architects and consultants in other countries;
- delivery in agreed CAD, BIM and open formats;
- integration with due diligence or renovation services.
Architectural surveying in Rome and throughout Italy
Farre+Stevenson provides architectural surveying services for properties in Rome and throughout Italy, including apartments, houses, commercial premises, historic buildings, offices, cultural spaces, terraces, gardens and larger existing complexes.
The survey may be commissioned as an independent service or integrated with architectural design, due diligence, feasibility studies, BIM, HBIM, interior architecture and landscape design.
Farre+Stevenson Architecture produces measured surveys and existing-condition documentation that transform on-site observations and measurements into reliable plans, sections, elevations, models and digital information for design, verification and management of the built environment.