# Solar Shading Design: Tai Po, Hong Kong

> How to research solar shading design for a specific site in Tai Po — the controlling authority, source documents, and checks to run before you rely on a number.

- Canonical: https://harth.build/resources/solar-data/solar-shading-design-tai-po-hk/
- Last updated: 2026-09-02
- Data source: Location data from the [GeoNames HK dump](https://download.geonames.org/export/dump/HK.zip) (CC BY 4.0, snapshot 2026-08-31, GeoNames ID 1818673). Regulatory starting point: [Hong Kong Buildings Department](https://www.bd.gov.hk/en/resources/codes-and-references/codes-and-design-manuals/index.html). Figures are illustrative — verify against the current locally adopted edition for the site. Solar-method context: [NOAA Solar Calculation Details](https://gml.noaa.gov/grad/solcalc/calcdetails.html); the Harth monthly table uses a simpler declination and geometric-daylight approximation whose stated limitations must be retained. Project-date refinement reference: [NREL Solar Position Algorithm](https://midcdmz.nrel.gov/spa/).

## Key facts

| Fact | Value |
| --- | --- |
| Location reference | 22.4501, 114.1688 (GeoNames ID 1818673; replace with surveyed project coordinates) |
| Administrative area | NTP (GeoNames snapshot code; confirm the competent local jurisdiction) |
| Regulatory starting point | Buildings Ordinance, subsidiary regulations, codes of practice, and practice notes (country-level context only; identify the competent local authority) |
| June-solstice solar-noon check | 89.0° (declination-only geometry; not an hourly obstruction model) |
| Equinox solar-noon check | 67.5° (declination-only geometry) |
| December-solstice solar-noon check | 44.1° (declination-only geometry; verify civil time and horizon) |
| Approximate daylight range | 10.6–13.4 hours (representative 21st-day geometry (December to June); excludes refraction and terrain) |

## Direct answer

For Tai Po at 22.4501, 114.1688, the declination-only solar-noon altitude is approximately 89.0° at the June solstice, 67.5° at an equinox and 44.1° at the December solstice. Refine these geometry checks with the project date, civil time, facade azimuth, terrain and local horizon. The reproducible location record is GeoNames ID 1818673 in administrative area NTP, at 22.4501, 114.1688; replace it with the surveyed parcel point before relying on the result. As a transparent geometry check, declination-only solar-noon altitude is about 89.0° at the June solstice, 67.5° at an equinox and 44.1° at the December solstice. Representative 21st-day geometry ranges from about 10.6 hours in December to 13.4 hours in June; this excludes atmospheric refraction, terrain and obstruction effects. The cited national authority is a discovery starting point; current local documents and a named qualified reviewer control project use of this solar shading design record.

*Content and cited inputs reviewed by [Scott Barrington](https://nz.linkedin.com/in/barrington), Harth founder and architectural technology specialist · Published 2026-08-26 · Updated 2026-09-02.*

## What must be verified for Tai Po?

Tai Po is represented here at approximately **22.4501, 114.1688** for discovery and workflow planning. A project address, parcel, elevation, exposure, authority, and submission date must replace that city-centre reference before design use.

## How should solar shading design be established?

1. Fix the surveyed site and local time basis.
2. Select an authoritative weather source or a named solar-position algorithm.
3. Record period, percentile or scenario and units.
4. Test sensitivity to elevation, exposure, urban form and horizon.
5. Save the source file, retrieval date and checker in the model record.

| Input | Project-specific evidence | QA question |
| --- | --- | --- |
| Site | surveyed coordinates, elevation and horizon | Does the point represent the building? |
| Weather/solar method | named dataset, algorithm, period and time basis | Are station, time zone and units explicit? |
| Design scenario | current and future scenario agreed by the team | Is an average being mistaken for an extreme? |
| Compliance | adopted local document and edition | Was applicability confirmed with the authority? |

## What are the limits of this worksheet?

This shading-workflow page is a project-starting worksheet, not a design value or approval. The controlling authority and qualified professionals for the Tai Po site remain authoritative.

## Tai Po monthly solar geometry check for solar shading design

| Representative date | Declination | Solar-noon altitude | Geometric daylight | Noon shadow / height |
| --- | ---: | ---: | ---: | ---: |
| 21 January | -20.14° | 47.41° | 10.838 h | 0.919 |
| 21 February | -11.23° | 56.32° | 11.373 h | 0.666 |
| 21 March | -0.40° | 67.15° | 11.978 h | 0.421 |
| 21 April | +11.58° | 79.13° | 12.648 h | 0.192 |
| 21 May | +20.14° | 87.69° | 13.162 h | 0.040 |
| 21 June | +23.45° | 89.00° | 13.377 h | 0.017 |
| 21 July | +20.44° | 87.99° | 13.181 h | 0.035 |
| 21 August | +11.75° | 79.30° | 12.658 h | 0.189 |
| 21 September | -0.20° | 67.35° | 11.989 h | 0.417 |
| 21 October | -11.75° | 55.80° | 11.342 h | 0.680 |
| 21 November | -20.44° | 47.11° | 10.819 h | 0.929 |
| 21 December | -23.45° | 44.10° | 10.623 h | 1.032 |

## Tai Po solar-geometry fingerprint at 22.4501, 114.1688

- **Tai Po, 21 January:** declination -20.14°, noon altitude 47.41°, zenith 42.59°, geometric daylight 10.838 hours, and vertical-object noon shadow ratio 0.919.
- **Tai Po, 21 February:** declination -11.23°, noon altitude 56.32°, zenith 33.68°, geometric daylight 11.373 hours, and vertical-object noon shadow ratio 0.666.
- **Tai Po, 21 March:** declination -0.40°, noon altitude 67.15°, zenith 22.85°, geometric daylight 11.978 hours, and vertical-object noon shadow ratio 0.421.
- **Tai Po, 21 April:** declination +11.58°, noon altitude 79.13°, zenith 10.87°, geometric daylight 12.648 hours, and vertical-object noon shadow ratio 0.192.
- **Tai Po, 21 May:** declination +20.14°, noon altitude 87.69°, zenith 2.31°, geometric daylight 13.162 hours, and vertical-object noon shadow ratio 0.040.
- **Tai Po, 21 June:** declination +23.45°, noon altitude 89.00°, zenith 1.00°, geometric daylight 13.377 hours, and vertical-object noon shadow ratio 0.017.
- **Tai Po, 21 July:** declination +20.44°, noon altitude 87.99°, zenith 2.01°, geometric daylight 13.181 hours, and vertical-object noon shadow ratio 0.035.
- **Tai Po, 21 August:** declination +11.75°, noon altitude 79.30°, zenith 10.70°, geometric daylight 12.658 hours, and vertical-object noon shadow ratio 0.189.
- **Tai Po, 21 September:** declination -0.20°, noon altitude 67.35°, zenith 22.65°, geometric daylight 11.989 hours, and vertical-object noon shadow ratio 0.417.
- **Tai Po, 21 October:** declination -11.75°, noon altitude 55.80°, zenith 34.20°, geometric daylight 11.342 hours, and vertical-object noon shadow ratio 0.680.
- **Tai Po, 21 November:** declination -20.44°, noon altitude 47.11°, zenith 42.89°, geometric daylight 10.819 hours, and vertical-object noon shadow ratio 0.929.
- **Tai Po, 21 December:** declination -23.45°, noon altitude 44.10°, zenith 45.90°, geometric daylight 10.623 hours, and vertical-object noon shadow ratio 1.032.

Harth computed the Tai Po fingerprint for latitude 22.4501° with the Cooper declination approximation, `90° - |latitude - declination|` at solar noon, centre-to-centre sunrise hour angle and `1 / tan(altitude)` shadow ratio. Longitude 114.1688° is retained for a later civil-time conversion; this screen does not perform that conversion. See [NOAA's solar calculation details](https://gml.noaa.gov/grad/solcalc/calcdetails.html). Atmospheric refraction, terrain, facade azimuth and obstructions remain outside this first-pass comparison.

## Where can you explore related guidance?

- [Explore all solar data guidance](https://harth.build/resources/solar-data.md)
- [Sun Path: Tai Po, Hong Kong](https://harth.build/resources/solar-data/sun-path-tai-po-hk.md)
- [Solar Altitude & Azimuth: Tai Po, Hong Kong](https://harth.build/resources/solar-data/solar-altitude-azimuth-tai-po-hk.md)
- [Daylight & Orientation: Tai Po, Hong Kong](https://harth.build/resources/solar-data/daylight-orientation-tai-po-hk.md)
- [Solar Shading Design: Fanling, Hong Kong](https://harth.build/resources/solar-data/solar-shading-design-fanling-hk.md)
- [All solar & daylight data guidance for Hong Kong](https://harth.build/resources/solar-data/hong-kong.md)
- [House Construction Cost Planning: Tai Po, Hong Kong SAR, China](https://harth.build/resources/construction-costs/house-construction-cost-tai-po-hk.md)
- [Office Construction Cost Planning: Tai Po, Hong Kong SAR, China](https://harth.build/resources/construction-costs/office-construction-cost-tai-po-hk.md)
- [Retail Construction Cost Planning: Tai Po, Hong Kong SAR, China](https://harth.build/resources/construction-costs/retail-construction-cost-tai-po-hk.md)
- [School Construction Cost Planning: Tai Po, Hong Kong SAR, China](https://harth.build/resources/construction-costs/school-construction-cost-tai-po-hk.md)

## Sources and method

Location data from the [GeoNames HK dump](https://download.geonames.org/export/dump/HK.zip) (CC BY 4.0, snapshot 2026-08-31, GeoNames ID 1818673). Regulatory starting point: [Hong Kong Buildings Department](https://www.bd.gov.hk/en/resources/codes-and-references/codes-and-design-manuals/index.html). Figures are illustrative — verify against the current locally adopted edition for the site. Solar-method context: [NOAA Solar Calculation Details](https://gml.noaa.gov/grad/solcalc/calcdetails.html); the Harth monthly table uses a simpler declination and geometric-daylight approximation whose stated limitations must be retained. Project-date refinement reference: [NREL Solar Position Algorithm](https://midcdmz.nrel.gov/spa/).

### Source links

- [download.geonames.org](https://download.geonames.org/export/dump/HK.zip)

- [bd.gov.hk](https://www.bd.gov.hk/en/resources/codes-and-references/codes-and-design-manuals/index.html)

- [gml.noaa.gov](https://gml.noaa.gov/grad/solcalc/calcdetails.html)

- [midcdmz.nrel.gov](https://midcdmz.nrel.gov/spa/)

## Frequently asked questions

### What does the solar shading design record for Tai Po establish?

The solar shading design record for Tai Po establishes a reproducible discovery point at 22.4501, 114.1688 (GeoNames ID 1818673, administrative area NTP) and a Hong Kong source path. It does not establish a final project value, approval or parcel decision.

### What must be replaced before using this solar shading design workflow for a project in Tai Po?

For the solar shading design record in Tai Po, replace the 22.4501, 114.1688 city reference with the surveyed site or parcel, identify the competent local authority, and verify the current documents under Buildings Ordinance, subsidiary regulations, codes of practice, and practice notes. Record the edition, retrieval date, units, assumptions and named checker before relying on the result.

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