Module 4: Site, Property, and Existing-Condition Information

For the progressive two-storey community/institutional building, architectural and structural drafting cannot be treated as reliable until the team knows what property is being designed on and what site geometry controls the work.

A drawing can look precise while being based on poor evidence. Examples include:

• tracing lot lines from an online basemap;
• using a fence as the legal boundary without survey confirmation;
• assuming that the road elevation is the project benchmark;
• copying utility lines from an old plan that has not been verified;
• assuming that a nearby drain establishes the permitted discharge point;
• using photographs to estimate floor elevations;
• reproducing an old renovation drawing without confirming that the building was constructed as shown.

The professional objective is not to collect the largest number of documents. It is to establish which evidence is current, authoritative, technically appropriate, and fit for the specific design decision.

Property records help establish the legal and documentary context of the site.

Useful records may include:

• current certified copy of title where applicable;
• lot, block, plan, and survey references;
• registered annotations affecting the property;
• technical description;
• approved survey plans or cadastral records where available;
• records concerning rights-of-way, easements, restrictions, or encumbrances;
• tax and local property records where relevant to project administration.

A title record and a field survey answer different questions. A title identifies the registered property and the matters stated in the registration record, while a competent geodetic survey locates or reconstructs the parcel geometry from the controlling technical description, approved survey information, monuments, control, and field evidence appropriate to the task. A survey plan is not, by itself, a conveyance or conclusive proof of ownership. Designers should not convert documentary references into field coordinates by assumption, and they should not treat a relocation or verification survey as an adjudication of a disputed ownership or boundary right.

Survey information may include:

• lot corner identifiers;
• bearings and distances;
• tie lines or reference information;
• survey plan number;
• surveyor or geodetic engineer information;
• approved-plan references;
• coordinate or control information;
• technical descriptions;
• lot area;
• adjoining parcels or roads;
• monuments and boundary evidence.

Under DENR Administrative Order No. 2007-29, isolated survey plans are prepared in prescribed formats and the original plans are signed and sealed by the Geodetic Engineer; a technical description for each lot is prepared upon approval of the survey plan and signed by the concerned Geodetic Engineer. The design team should preserve the plan identity, approval/status information, and source rather than redrawing the parcel and losing its provenance.

If different survey records disagree, the correct response is not to average the values. Open a discrepancy, identify the controlling source or obtain competent verification.

Bearings and distances describe survey geometry. Their correct use depends on the source survey, reference system, and professional interpretation.

Before using them in a design base, establish:

• which survey or technical description they came from;
• whether the information is approved or otherwise authoritative for the intended purpose;
• whether the lot corners have been verified or recovered in the field;
• what coordinate or reference system is being used;
• whether transformations or legacy datums are involved;
• whether the plotted parcel agrees with the current field survey;
• how project control will be related to the parcel.

Do not infer a coordinate system from the appearance of a drawing.

Elevation data requires the same discipline as horizontal location.

The Project Base File should identify:

• the benchmark used;
• benchmark description and physical location;
• source of the benchmark elevation;
• vertical datum or reference basis;
• survey date;
• relationship between survey levels and architectural project levels;
• any local temporary benchmark established for construction;
• checks performed before the benchmark is reused.

A project level such as “Ground Floor = 0.000” is a design convention. It becomes meaningful in the real world only when its relationship to the verified site elevation datum is defined.

A topographic survey should capture the features needed for the actual project, which may include:

• ground elevations;
• contours or spot levels;
• road and curb levels;
• drainage channels and inlets;
• existing buildings and structures;
• walls, fences, and major improvements;
• trees and significant vegetation;
• poles, manholes, hydrants, visible utility features, or service entries;
• watercourses and drainage paths;
• slope breaks;
• adjacent features that materially affect access, drainage, retaining, or construction.

Contour interval and survey extent should be appropriate to the site and design need. A small urban parcel, steep hillside, flood-sensitive site, or large campus may require different field detail and survey extent.

Design does not stop at the lot line when external conditions control the project.

Investigate:

• legal and physical access;
• public or private road relationship;
• road width and edge condition;
• curb, gutter, sidewalk, and drainage;
• adjoining building proximity;
• retaining walls or slope conditions;
• gates and delivery access;
• emergency and service access requirements;
• construction access and staging constraints;
• potential rights-of-way or easements.

The existence of a visible path or driveway does not establish a legal access right. Likewise, a mapped right-of-way must be related to actual field conditions before it is used for design.

For renovation, alteration, addition, or adaptive reuse, existing drawings are evidence—not proof that the built structure matches the documents.

A controlled existing-condition investigation may include:

• original and revised drawings;
• as-built or record drawings;
• permits and prior alteration records;
• field measurements;
• structural framing observations;
• material and condition observations;
• equipment and service locations;
• photographs with location and date;
• intrusive investigation where justified and properly authorized;
• survey control for the existing building;
• discrepancy records between drawings and field conditions.

Concealed conditions should remain identified as unknown until exposed, tested, surveyed, or otherwise competently verified.

Utility information can come from client records, visible site features, utility providers, prior surveys, scanning or detection work, field investigation, and other sources.

Record, where relevant:

• water service;
• sanitary sewer or septic systems;
• storm drainage;
• electrical supply;
• communications;
• gas or fuel systems where applicable;
• site lighting;
• underground and overhead lines;
• manholes, vaults, meters, poles, transformers, and service entries.

Utility plans may be incomplete or schematic. Before excavation, relocation, connection, or detailed coordination, the team should obtain the level of verification appropriate to the consequence of error.

Subsurface utility information has a reliability problem that must remain visible in the design basis.

• As-built or record drawings may be incomplete, schematic, superseded, or different from the actual installed condition.
• Utility-provider records can identify expected systems, service information, or approximate routes, but they do not necessarily prove the current horizontal position, depth, condition, or presence of every underground line.
• Visible appurtenances such as manholes, poles, meters, valves, boxes, and service entries provide useful clues but do not by themselves establish the full underground alignment or depth between visible points.
• Detection or utility-locating methods may improve the evidence where appropriate, but their suitability and limitations depend on the utility type, site conditions, equipment, operator competence, and project risk.
• Surveyed locations provide controlled position for features that have actually been located or exposed; a surveyed symbol should not imply that an unseen utility was physically verified when it was only inferred.
• Physical exposure or verification, such as an authorized test pit, pothole, or other controlled investigation, may be justified where consequence of error is high, but the method must be selected and performed under the project's safety, utility-owner, excavation, permit, and professional requirements.

A useful evidence progression is:

Evidence hierarchy: provider/record information → site reconnaissance → utility locating where appropriate → surveyed location evidence → authorized physical verification where justified → controlled Project Base File update.

Site drainage understanding may require more than identifying existing pipes.

Review:

• high and low points;
• apparent overland flow paths;
• roof discharge locations;
• road and gutter levels;
• existing channels and inlets;
• receiving drainage system;
• adjacent runoff;
• erosion evidence;
• ponding evidence;
• historical flooding information;
• topographic controls;
• proposed grading implications.

A photograph taken on a dry day cannot establish flood behavior. Historical evidence, official hazard information, survey data, drainage analysis, and local observations can each contribute different evidence.

Major trees, rock outcrops, retaining walls, waterways, monuments, utility structures, neighboring improvements, and other physical features can affect layout, excavation, access, drainage, safety, or permitting.

The base file should distinguish:

• feature observed in the field;
• feature surveyed;
• feature shown on an old plan;
• feature whose legal or regulatory significance still requires confirmation.

Do not assign protected status, ownership, or removal permission solely from visual observation.

Early site screening should identify evidence of hazards that may require specialist investigation or design response.

Examples include:

• mapped flood susceptibility;
• landslide susceptibility;
• steep or unstable slopes;
• erosion;
• seismic and fault-related hazards;
• volcanic hazards where relevant;
• coastal or river hazards;
• fill, made ground, or uncertain ground conditions;
• adjacent retaining or excavation risks.

Official hazard maps and government hazard platforms are screening inputs, not project-specific design investigations. A mapped susceptibility class does not, by itself, establish foundation parameters, slope stability, flood elevations, design discharges, drainage capacity, groundwater conditions, or a site-specific structural response. Where those matters control the project, the responsible team must obtain the appropriate geotechnical, hydrologic/hydraulic, survey, structural, or other specialist investigation.

HazardHunterPH provides multi-agency government hazard information and can support preliminary screening. HazardHunterPH itself describes its generated assessments as indicative; official hazard-assessment documents should be requested from the concerned mandated agency when the project or approving authority requires them. Whether or not an official hazard record is obtained, the project team must still assess the source, scale, date, limitations, and whether project-specific investigation is needed for the actual design decision.

Geotechnical information may include:

• borehole or test-pit logs;
• laboratory test results;
• subsurface profiles;
• groundwater observations;
• engineering parameters;
• foundation recommendations;
• excavation and retaining considerations;
• slope-stability information;
• liquefaction or seismic-site considerations where relevant;
• limitations and recommended further investigation.

The structural or civil designer should not invent soil parameters because the architectural layout is already progressing. When a design decision depends materially on ground behavior, obtain appropriate geotechnical evidence and professional interpretation.

Site photographs are useful when they preserve context.

A good photographic record identifies:

• date;
• location or viewpoint;
• direction of view;
• subject;
• relevant scale or dimension where needed;
• relationship to survey or drawing references;
• photographer or source;
• whether the condition was directly observed or supplied by another party.

Photographs should supplement measurement and professional investigation, not substitute for them.

Every important site datum should be classified.

• Client-supplied information: received from the client or owner. It may be useful but is not automatically verified.
• Field-observed information: directly observed on site. It describes visible conditions but may not establish concealed, legal, or surveyed facts.
• Officially sourced records: issued or certified by an authority or official custodian for a defined purpose.
• Verified survey information: produced or verified through competent geodetic surveying appropriate to the required decision.
• Assumptions requiring confirmation: provisional information explicitly marked for later verification.

The class should remain visible in the project record until the information is superseded by a more authoritative source.

Examples include:

• title or parcel identity not reconciled with the survey;
• boundary geometry unresolved;
• benchmark or vertical datum unknown;
• topographic survey does not cover the required design extent;
• road or access relationship uncertain;
• utility location or connection point unverified where it controls design;
• existing building dimensions conflict with record drawings;
• concealed structural condition required for alteration remains unknown;
• geotechnical information is absent where foundation or slope decisions depend on it;
• official hazard information identifies a concern requiring specialist evaluation;
• contradictory source documents have not been resolved.

A team may continue non-dependent work, but the drawings should not conceal the unresolved basis.

A utility record and a recent site survey show different levels for the same connection. Do not average the values or select the more convenient one.

First compare point identity, datum, units, observation date, source authority, and whether each value is measured, designed, or recalled. Assign a verification task to the appropriate party and identify every drawing that depends on the unresolved level. Keep preliminary studies explicitly provisional; hold the affected gravity connection and construction issue until the controlling value is resolved. Preserve both source records and the resolution so the selected level remains traceable after the base file is updated.

• Republic Act No. 8560 — Philippine Geodetic Engineering Act of 1998 — Lawphil; statutory scope of geodetic engineering and surveying activities.
• Republic Act No. 9200 — Amendment to the Philippine Geodetic Engineering Act of 1998 — Lawphil; amends R.A. No. 8560, including geodetic-engineering consultancy and requirements for survey-plan submission using government-prescribed numbering and projection.
• Heirs of Aurio T. Casiño, Sr. v. Development Bank of the Philippines and Green River Gold, Inc., G.R. Nos. 204052-53, March 11, 2020 — Supreme Court; reiterates that a survey plan is not a conveyance, a mode of acquiring ownership, or conclusive evidence of ownership.
• DENR Administrative Order No. 2007-29 — Revised Regulations on Land Surveys — Department of Environment and Natural Resources; regulations addressing survey plans, survey returns, technical descriptions, and land-survey administration.
• DENR NCR IVAS Corner — Department of Environment and Natural Resources; current land-survey administration resources including survey-return, LAMS/e-survey, and DAO 2007-29 materials.
• LRA eSerbisyo — Land Registration Authority; official online service for requesting Certified True Copies of land titles.
• NAMRIA Geodetic Services — National Mapping and Resource Information Authority; official surveying, mapping, geodetic, and benchmark-related services.
• NAMRIA Products and Geodetic Control Services — National Mapping and Resource Information Authority; official products and services including geodetic control points and topographic mapping.
• NAMRIA PAGeNet Services and Reference Frames — National Mapping and Resource Information Authority; current GNSS reference-frame and correction-service information.
• HazardHunterPH — About and limitations — GeoRisk Philippines / DOST-PHIVOLCS; identifies the platform as an indicative multi-agency hazard-assessment tool and directs users to mandated agencies for official hazard reports.