Donal Lennon - Academia.edu (original) (raw)

Papers by Donal Lennon

Proponents of Passivhaus and nZEB often emphasise a 'fabric first approach' to ensure optimum env... more Proponents of Passivhaus and nZEB often emphasise a 'fabric first approach' to ensure optimum envelope design, and by extension highest building energy performance. The energy performance of two similar walls, of two separate nZEB-compliant dwellings, are assessed in this paper. The walls have similar construction details, consisting of a layer of 200 mm of mineral wool on the exterior side and a block construction on the interior. The walls are investigated by comparing theoretical and in-situ conductance values while also estimating the embodied energy of both walls. The study found that, although the walls were of similar design and the test was conducted using the same methodology (in accordance with ISO 9869-1), that there was a significant different between the in-situ performance of both walls. One wall performed only slightly worse than the design value while the other performed more than two times worse. This research extrapolates on the findings by comparing theoretical heat loss scenarios with both wall types and calculates A) the potential building energy performance for both walls and B) the carbon and energy payback for the insulation used to achieve such high performance. The results demonstrate the importance of good practice in construction of the building envelopes and in the manufacturing, robustness and quality control of the various building components.

The Europe Union needs to reduce its carbon emissions. To achieve the proposed 55% emission reduc... more The Europe Union needs to reduce its carbon emissions. To achieve the proposed 55% emission reduction target by 2030 it has embarked on a Renovation Wave which aims for more, and deeper, building renovation. Considering this ambition and the scale of the challenge, there remains a surprising paucity of documented post occupancy evaluation studies of deep retrofit projects, particularly those related to the new nZEB standards and of group housing schemes. This paper reports on the post-retrofit performance of a community of 12 single story, one bedroom social houses located in the southeast of Ireland, occupied by retired and elderly tenants. The deep retrofit works included the upgrade of the building fabric, ventilation and heating, all with a view to transforming the living standards of the occupants. They in turn responded, when surveyed, with near unanimous satisfaction. The upgrade and the addition of onsite microgeneration ensured these houses were transformed from lowly F and G national building energy ratings (BER) to A rated homes as calculated by the national energy rating software, DEAP. However, a performance gap is reported between the expected A performance (<75 kWh/m 2 /yr) and the actual performance, with some homes consuming more than twice the predicted energy, while in one extreme case the mean winter indoor temperatures are more than 7°C above the operating temperatures assumed by the DEAP software. The higher than expected indoor temperatures are directly correlated with the higher than expected energy consumption, consumed by a heat pump which in itself exhibited inefficiencies in operation. This post occupancy evaluation, post retrofit, provides evidence therefore of high occupant satisfaction, but a satisfaction based on significant energy 'underperformance'. This case study provides evidence and insights that can help guide future retrofit practices as Ireland progresses towards the transformation of its building stock to near Zero Energy Buildings (nZEB). It also opens up serious questions around the aims and expectations of our national nZEB standard and generates some key insights into the energy consumption of nZEB dwellings and the assessment methods necessary to measure them accurately.

PDF poster with historical summary, plan view of LiDAR scan data, and perspective image for Slade... more PDF poster with historical summary, plan view of LiDAR scan data, and perspective image for Slade Harbour.

LAS (LASer file format) point cloud of Slade Harbour created using onsite LiDAR laser scans.

This collection contains files which describe the construction and evolution of Slade Harbour, Co... more This collection contains files which describe the construction and evolution of Slade Harbour, County Wexford, from its earliest structure to its current form.

PDF poster with historical summary, plan view of LiDAR scan data, and perspective image for Fetha... more PDF poster with historical summary, plan view of LiDAR scan data, and perspective image for Fethard Harbour.

LAS (LASer file format) point cloud of Fethard Harbour created using onsite LiDAR laser scans.

This collection contains files which describe the construction and evolution of Fethard Harbour, ... more This collection contains files which describe the construction and evolution of Fethard Harbour, County Wexford, from its earliest structure to its current form.

PDF poster with historical summary, plan view of LiDAR scan data, and perspective image for Boats... more PDF poster with historical summary, plan view of LiDAR scan data, and perspective image for Boatstrand Harbour.

LAS (LASer file format) point cloud of Boatstrand Harbour created using onsite LiDAR laser scans.

This collection contains files which describe the construction and evolution of Boat Strand Harbo... more This collection contains files which describe the construction and evolution of Boat Strand Harbour, County Waterford, from its earliest structure to its current form.

LAS (LASer file format) point cloud of Port Oriel Harbour created using onsite LiDAR laser scans.

This collection contains files which describe the construction and evolution of Port Oriel Harbou... more This collection contains files which describe the construction and evolution of Port Oriel Harbour, County Louth, from its earliest structure to its current form.

PDF poster with historical summary, plan view of LiDAR scan data, and perspective image for Bullo... more PDF poster with historical summary, plan view of LiDAR scan data, and perspective image for Bullock Harbour.

LAS (LASer file format) point cloud of Bullock Harbour created using onsite LiDAR laser scans.

This collection contains files which describe the construction and evolution of Bullock Harbour, ... more This collection contains files which describe the construction and evolution of Bullock Harbour, County Dublin, from its earliest structure to its current form.

PDF poster with historical summary, plan view of LiDAR scan data, and perspective image for Balbr... more PDF poster with historical summary, plan view of LiDAR scan data, and perspective image for Balbriggan Harbour.

This collection contains files which describe the construction and evolution of Balbriggan Harbou... more This collection contains files which describe the construction and evolution of Balbriggan Harbour, County Fingal, from its earliest structure to its current form.

Minor Harbours of Ireland, an Irish Research Council-funded project by UCD School of Architecture... more Minor Harbours of Ireland, an Irish Research Council-funded project by UCD School of Architecture, Planning and Environmental Policy, examines the evolution of maritime engineering in small harbours in Ireland from the seventeenth century to the present. This collection records the construction and evolution of a selection of these minor harbours and includes short historical descriptions, onsite LiDAR scans, photographic site surveys, and exhibition posters for each harbour.

LAS (LASer file format) point cloud of Balbriggan Harbour created using onsite LiDAR laser scans.

Proponents of Passivhaus and nZEB often emphasise a 'fabric first approach' to ensure optimum env... more Proponents of Passivhaus and nZEB often emphasise a 'fabric first approach' to ensure optimum envelope design, and by extension highest building energy performance. The energy performance of two similar walls, of two separate nZEB-compliant dwellings, are assessed in this paper. The walls have similar construction details, consisting of a layer of 200 mm of mineral wool on the exterior side and a block construction on the interior. The walls are investigated by comparing theoretical and in-situ conductance values while also estimating the embodied energy of both walls. The study found that, although the walls were of similar design and the test was conducted using the same methodology (in accordance with ISO 9869-1), that there was a significant different between the in-situ performance of both walls. One wall performed only slightly worse than the design value while the other performed more than two times worse. This research extrapolates on the findings by comparing theoretical heat loss scenarios with both wall types and calculates A) the potential building energy performance for both walls and B) the carbon and energy payback for the insulation used to achieve such high performance. The results demonstrate the importance of good practice in construction of the building envelopes and in the manufacturing, robustness and quality control of the various building components.

The Europe Union needs to reduce its carbon emissions. To achieve the proposed 55% emission reduc... more The Europe Union needs to reduce its carbon emissions. To achieve the proposed 55% emission reduction target by 2030 it has embarked on a Renovation Wave which aims for more, and deeper, building renovation. Considering this ambition and the scale of the challenge, there remains a surprising paucity of documented post occupancy evaluation studies of deep retrofit projects, particularly those related to the new nZEB standards and of group housing schemes. This paper reports on the post-retrofit performance of a community of 12 single story, one bedroom social houses located in the southeast of Ireland, occupied by retired and elderly tenants. The deep retrofit works included the upgrade of the building fabric, ventilation and heating, all with a view to transforming the living standards of the occupants. They in turn responded, when surveyed, with near unanimous satisfaction. The upgrade and the addition of onsite microgeneration ensured these houses were transformed from lowly F and G national building energy ratings (BER) to A rated homes as calculated by the national energy rating software, DEAP. However, a performance gap is reported between the expected A performance (<75 kWh/m 2 /yr) and the actual performance, with some homes consuming more than twice the predicted energy, while in one extreme case the mean winter indoor temperatures are more than 7°C above the operating temperatures assumed by the DEAP software. The higher than expected indoor temperatures are directly correlated with the higher than expected energy consumption, consumed by a heat pump which in itself exhibited inefficiencies in operation. This post occupancy evaluation, post retrofit, provides evidence therefore of high occupant satisfaction, but a satisfaction based on significant energy 'underperformance'. This case study provides evidence and insights that can help guide future retrofit practices as Ireland progresses towards the transformation of its building stock to near Zero Energy Buildings (nZEB). It also opens up serious questions around the aims and expectations of our national nZEB standard and generates some key insights into the energy consumption of nZEB dwellings and the assessment methods necessary to measure them accurately.

PDF poster with historical summary, plan view of LiDAR scan data, and perspective image for Slade... more PDF poster with historical summary, plan view of LiDAR scan data, and perspective image for Slade Harbour.

LAS (LASer file format) point cloud of Slade Harbour created using onsite LiDAR laser scans.

This collection contains files which describe the construction and evolution of Slade Harbour, Co... more This collection contains files which describe the construction and evolution of Slade Harbour, County Wexford, from its earliest structure to its current form.

PDF poster with historical summary, plan view of LiDAR scan data, and perspective image for Fetha... more PDF poster with historical summary, plan view of LiDAR scan data, and perspective image for Fethard Harbour.

LAS (LASer file format) point cloud of Fethard Harbour created using onsite LiDAR laser scans.

This collection contains files which describe the construction and evolution of Fethard Harbour, ... more This collection contains files which describe the construction and evolution of Fethard Harbour, County Wexford, from its earliest structure to its current form.

PDF poster with historical summary, plan view of LiDAR scan data, and perspective image for Boats... more PDF poster with historical summary, plan view of LiDAR scan data, and perspective image for Boatstrand Harbour.

LAS (LASer file format) point cloud of Boatstrand Harbour created using onsite LiDAR laser scans.

This collection contains files which describe the construction and evolution of Boat Strand Harbo... more This collection contains files which describe the construction and evolution of Boat Strand Harbour, County Waterford, from its earliest structure to its current form.

LAS (LASer file format) point cloud of Port Oriel Harbour created using onsite LiDAR laser scans.

This collection contains files which describe the construction and evolution of Port Oriel Harbou... more This collection contains files which describe the construction and evolution of Port Oriel Harbour, County Louth, from its earliest structure to its current form.

PDF poster with historical summary, plan view of LiDAR scan data, and perspective image for Bullo... more PDF poster with historical summary, plan view of LiDAR scan data, and perspective image for Bullock Harbour.

LAS (LASer file format) point cloud of Bullock Harbour created using onsite LiDAR laser scans.

This collection contains files which describe the construction and evolution of Bullock Harbour, ... more This collection contains files which describe the construction and evolution of Bullock Harbour, County Dublin, from its earliest structure to its current form.

PDF poster with historical summary, plan view of LiDAR scan data, and perspective image for Balbr... more PDF poster with historical summary, plan view of LiDAR scan data, and perspective image for Balbriggan Harbour.

This collection contains files which describe the construction and evolution of Balbriggan Harbou... more This collection contains files which describe the construction and evolution of Balbriggan Harbour, County Fingal, from its earliest structure to its current form.

Minor Harbours of Ireland, an Irish Research Council-funded project by UCD School of Architecture... more Minor Harbours of Ireland, an Irish Research Council-funded project by UCD School of Architecture, Planning and Environmental Policy, examines the evolution of maritime engineering in small harbours in Ireland from the seventeenth century to the present. This collection records the construction and evolution of a selection of these minor harbours and includes short historical descriptions, onsite LiDAR scans, photographic site surveys, and exhibition posters for each harbour.

LAS (LASer file format) point cloud of Balbriggan Harbour created using onsite LiDAR laser scans.