Everything you need to know

Please use our "Map It" tool to request a price for your specific site and survey requirements. Alternatively please send an email to surveys@topographical.co.uk along with a plan of the area that the survey is required for along with any specification documents.

We work nationally, most commonly in Nottinghamshire, Derbyshire, Leicestershire, Lincolnshire, Rutland, Staffordshire, Northamptonshire & South Yorkshire. Thanks to our online nature, efficient workflows and low overheads, we have successfully tendered for topographic land and surveys & measured building survey projects all over mainland UK

Please go to our Services page to view samples of the type of survey you are interested in. Many projects are ongoing and sensitive in nature, so please get in touch if you don't see what you are looking for and we can prepare a relevant sample that does not jeapordise other clients' sensitive information.

We try to keep a healthy lead time of 1-2 weeks but we will accommodate small jobs with a quick turnaround where possible.

Most topographic, surveys will include both 2D & 3D .DWG cad drawings, PDF layouts/plots from the 2D model and any other supporting files. We will ultimately customise our proposal to your specification and we can provide data in a wide range of formats.

Existing mapping of the wider area can provide context to your topographical or measured building survey, but it is not compulsory. We’ll sometimes display it in the background, usually coloured in light grey. For boundary surveys, this is usually required to meet Land Registry requirements. Any costs for additional data will be itemised in the quote.

Otherwise known as a coordinate reference system. For most surveys, the survey should relate to the Ordnance Survey National Grid. If you’re adding to or checking an historic survey, then please upload/email your existing survey so that we can review the best way forward.

Please combine all existing plans, surveys and photographs into a single file. You can do this by creating a .zip file. 1. Place all the relevant files in a folder together on your computer. 2. Right click the folder and locate the option “Send to > Compressed (zipped) folder”.

We have developed an easy to manipulate and optimally fragmented layering system for ease of use by architects and engineers using standard CAD. For public sector projects we have a BIM compliant system. Please advise us of any specific cad format requirements at the quote stage.

The viewpoint symbol contains a link to a photo or video file. Hover your mouse over the viewpoint, hold CTRL on your keyboard and left click on your mouse to open the file. Remember to keep all the files in the folder structure we sent or the image files and other external references such as base mapping will require re-linking.

Yes. As standard, we will report volumes on any formal and graded stock piles surveyed within your survey area. The calculation assumes the base to base method and does not apply a bulking factor. For anything more specific please ask.

Yes. We are trained and insured to perform setting out. Please email or upload ("Map It") your coordinate file/design drawing. Let us know about any material usage or reporting required and we'll get back to you with a competitive quote.

Yes, to Environment Agency specification, or your own, for modelling and flood risk assessment purposes. View our Services page for more information.

We work closely with specialist underground surveyors and buried services surveyors who support us in providing utility mapping services to our clients.

Our Leica equipment is regularly calibrated by independent, Leica qualified technicians. On site checks are made each day to ensure equipment is functioning within tolerances. Calibration certificates can be provided for equipment used on your project.

Absolutely accuracy refers to how accurate a survey measurement is - within a specific coordinate system. For example, a determined boundary survey for Land Registry should have an absolute accuracy within Ordnance Survey National Grid of 300 mm (0.3 metres)

Relative accuracy refers to how accurate the survey measurements are in relation to each other. For example, the relative accuracy of a determined boundary plan should be +/- 10mm (0.010 metres). So the position of a fence, compared to a building corner, should be very accurate - even though overall the survey only needs to fit the Ordnance Survey map within 300mm (see above).

Imagine stopping to ask somebody for directions and being told "just keep going for 5 miles". To be safe, you then wait for another passer by and check with them. They say "It's 4.32 miles ahead". When you get there, you check the odometer and it reads 5.13 miles. The first helper was quite accurate, but not very precise. The second helper gave a very precise distance, but it wasn't accurate. An accurate AND precise answer would have been "it's 5.13 miles ahead".

Survey data is rarely delivered without some adjustment to provide a best estimate on final coordinates. The Bowditch and Least Squares method are commonly applied in land surveying.

This can range from historic aerial photography which can be used as evidence in a boundary survey, to high resolution drone survey images and video, which can be processed into 3d maps, models and orthophotos.

Benchmarks are an antiquated network of permanent marks/markers positioned around the UK to provide a reference height above Ordnance Survey Datum (mean sea level). Since the advent of GPS technology, these are longer updated or maintained - however the historic height values can still be obtained.

Bulking refers to the expansion of materials after excavation where shrinkage refers to the opposite effect when material is compacted. Volume analysis of stockpiles and cut and fill exercises for earthworks should be mindful of the materials being measured and whether or not correction factors are to be applied.

Contours can be useful in 2D and 3D, but they traditionally represent 3D information (elevation or height of land), in a 2D format. Horizontal curved lines connect points on the map with the same elevation values - which allow the terrain to be interpreted. Experience reading contour maps allows you to visualise the lay of the land in 3d, using a 2d medium.

Survey control points, together referred to as the control network, are the most precisely measured points during a survey. Usually marked permanently with pins, nails, stakes and spray paint, these accurate points have precise coordinates which allow the survey to be revisited for future works and checked for accuracy.

Most surveys will incorporate some control, but a control survey is only concerned with establishing a robust and well referenced control network for other survey works to be carried out from. Recommended as a first step for larger sites and areas, this ensures an adequate framework is installed before hundreds of hours are invested in carrying out detail survey works (mapping the features).

Coordinates in surveying are typically 2 number strings (X & Y axis) or 3 number strings (X, Y & Z) which describe the spatial position and/or elevation or height of a point, within a coordinate reference system. The national system for Great Britain is called OSGB36 for the X (easting) and Y (Northing) axis, with orthometric heights relative to Ordnance Datum Newlyn (Mean Sea Level)

A datum is a reference point or surface. Heights (elevations) of other points on the map or survey are relative to the datum. Most surveys in mainland UK use mean sea level as a 0.00 datum, so a level of 50.00 means 50 meters above mean sea level. Local arbitrary datums are sometimes used instead, such as a finished floor level or a man hole cover frame.

A determined boundary application to Land Registry consists of a plan prepared by a qualified land surveyor acting on behalf, or with agreement from both parties (either side of the boundary). Evidence to support the plan should be included in the application. It is a more precise description of the exact line of the boundary than the red line, general boundary found on a common title plan.

All of these digital or computerised models contain varying degrees of detail about the position and heights of features in the survey area. Elevation models typically contain a grid of spot heights (only at ground level), where as surface models will include elevated features such as tree canopies and building roofs. A DTM (digital terrain model) is a more detailed elevation model, including linework for features such as banks, rivers, roads and other features. A land surveyor will typically produce a DTM of a survey area when producing a topographical survey and may use 3rd party data from a digital elevation model to provide information on off site areas without access. Historic surface models may be useful to mass model structures which were not modelled before demolition.

Yes Earth is "round". Though this generally only becomes relevant when surveying large areas - when this curvature may need to be accounted for, depending on the purpose of the survey.

Easements may be relevant when producing title plans for land registry or undertaking a boundary survey. They are a legal right, typically allowing access or use of (servient) land by the owner of other (dominant) land. They may be described in the title register and/or indicated on the title plan or first conveyance document.

An elevation is the height of a feature in land surveying, usually above mean sea level. However it can become confusing as building façade drawings (also carried out by land surveyors when performing a measured building survey) are commonly referred to as "elevations" by architects and planning professionals. Elevation drawings show the heights of the features present on the facade of a building, such as windows, doors and roof details.

Land surveyors are now blessed with an abundance of technological advancements - but a good understanding of the source of errors is still paramount to delivering accurate and reliable survey data. These sometimes carry different names, but include natural errors (e.g. atmosphere,refraction), Instrumental errors (incorrect calibration of equipment) and human errors (e.g. poor vision). These must all be accounted for appropriately depending on the accuracy requirements of the project. Blunders, or Gross Errors are essentially mistakes often caused by fatigue or inexperience. They are typically the most catastrophic, due to their often large size but this also makes them very easy to spot with sufficient quality control procedures.

First registration is an application process required by Land Registry when a conveyance is prepared for land that is previously unregistered. A title plan may need to be produced by a land or boundary surveyor, depending on what historic evidence is available.

The formation level in construction, is the surface where excavation is completed and construction can begin, usually starting with the sub base layer. A typical greenfield site will require a top soil strip and reduced level dig (cut) or fill to reach the formation level. Some groundworks contracts include the initial stages of construction as part of the works. Land surveyors and setting out engineers help to achieve the correct cut and fill of a site and provide volumes and calculations for quantity survey control. On larger sites, much of this work is now carried out by machine control.

A general boundary is used on the majority of Land Registry Title Plans. It is accompanied with a disclaimer and means that the red line does not indicate where the legal boundary is exactly, rather that the legal boundary is in the general vicinity of the red line general boundary.

GPS is a type of Global Navigation Satellite System. A number of such systems now exist as more satellites are launched by different organisations each year. Land Surveyors use this technology to achieve accurate measurements where there is a clear view to satellites and to establish the elevation of a site above mean sea level.

The hedge and ditch rule implies that where a hedge lies between land and a ditch, the ditch also belongs to the owner of the land. The underlying premise is that the current (or a previous) landowner dug the ditch immediately adjacent to the boundary line and planted a hedge on the excavated soil deposited within their own parcel. This is a simplified example and many other factors may come into play in determining if this rule can apply.

Levelling refers to measuring or setting the elevation or height of control points, relative to the datum. On a typical topographical survey or measured building survey, the accuracy of a modern total station is sufficient to set these elevations. For higher order accuracy work, such as large control networks, monitoring or simply where planimetric (X/Y) control is not required, "hard levelling" with a digital or optical level and graduated staff is used to complete a level loop. Obtaining a grid of spot heights, or levels over an area of land or concrete, may also be referred to as "levelling" the area.

Local scale factor is a multiplier that is applied to survey measurements on some surveys, to respect the curvature of the earth, within the projection/coordinate system/grid being used.

A monitoring project will typically consist of an initial installation of a control network placed on stable monuments outside of the area of interest. This is followed by careful installation and recording of the position and height of monitoring points. These are placed on features of interest within the monitoring area, or the entire monitoring area will be scanned with a 3d scanner. A series of subsequent monitoring surveys are carried out at prescribed intervals to repeat the measurement process and monitor changes in coordinates, representing movement and deflection.

Photogrammetry is the process of image capture and processing to allow measurements to be taken from photographs. Commonly used at ground level for building facades and aerially from camera equipped drones, a number of survey and mapping tasks can be completed or benefited by this method.

An orthophoto is an output of photogrammetry - an image is created from several ground or aerial photographs which are combined to create a scaled and stitched building facade or map . Unlike a single photograph which contains distortion and perspective, relatively accurate measurements can be taken from an orthophoto map. As orthophotos also show everything visible from above and in colour, they are an excellent complement to digital terrain models and the linework shown in a typical topographical survey, roof survey or stockpile and volume survey.

A point cloud is an output, deliverable or result from a survey which has deployed mass data collection methods such as laser scanning or photogrammetry. Up to millions of points are contained within the point cloud file, with or without colour. A point cloud viewer allows the file to be viewed in a digital 3d environment, where further modelling, measurement or inspection can be carried out. Point clouds underpin a number of reality capture solutions and offer a tool for surveyors to gather the data for 2d drawings efficiently and safely in some cases.

Modern total stations allow the surveyor to measure most surfaces without the need of a reflective prism. These are called reflectorless or remote measurements. Typically used on topographical surveys when the ground level isn't required, such as to measure building positions on private land, ridge and eave heights, over head cables and tree canopy levels. Land surveyors are less concerned with the ground level for every measurement when undertaking measured building surveys and boundary surveys. In the interests of accuracy and efficiency, reflectorless methods are used much more on these types of survey.

These are general heights/levels/elevations taken at a single point, usually in a grid format over a survey area.

A title plan usually accompanies the title register at Land Registry. It is a drawing showing the land which is described in the title register, usually edged in red (indicating only a general boundary line). You can request your title plan from Land Registry for a small charge. If you are working with a solicitor or boundary surveyor, they may have already obtained relevant title information to carry out the works.

Traversing is a process used by land surveyors to establish control networks and to move their equipment about a site to enable further measuring to be carried out. Usually consisting of three tripods, two tripods are used as a baseline to measure a new position under the third tripod. This third tripod can then be used as part of a new baseline, while the furthest back tripod is picked up and carried forward to be the new position, and so on. Ideally traverses should be closed on themselves (a loop) or to known points, to allow errors to be identified and distributed appropriately.